The Fair Work Commission received 16,500 unfair dismissal applications in 2024-25. That made unfair dismissal the single most common matter before the Commission, at 37 per cent of everything lodged that year. A striking number of those cases turn not on whether the employee did what they were accused of, but on how the employer went about finding out. When the workplace investigation process breaks down, the investigation itself becomes the thing the business has to defend.
This guide explains how to conduct a workplace investigation from start to finish, and sets out the investigation process step by step: planning and scoping, putting allegations in writing, holding procedural fairness through every stage, interviewing the complainant, the respondent and witnesses, weighing evidence on the correct standard of proof, making findings of fact, and reporting so the organisation can act. It is written for employers and HR practitioners dealing with allegations of misconduct, bullying, harassment or sexual harassment, and it stays at the level of general principles drawn from authoritative guidance. It is not legal advice, and serious matters warrant advice on their own facts.
What this guide covers, and what it leaves out
A workplace investigation is a formal fact-finding process. Its job is to establish, on the available evidence, whether alleged conduct occurred. A formal investigation of this kind is not a disciplinary process, a mediation or a performance conversation, although its findings will often feed one of those. Employers conduct workplace investigations into allegations of workplace misconduct, bullying, harassment and safety breaches, and the same investigation process applies across all of them.
Two related questions sit outside this guide. Whether a workplace investigation is required at all, rather than a less formal resolution, is a threshold judgment that deserves its own article. The immediate steps in the days after a complaint first lands, before anyone has decided whether to investigate, are covered in the Brookvale HR Solutions guidance on responding when an employee raises a complaint. This article begins where the decision to investigate has already been made.
Step 1: Plan and scope the investigation
Every procedurally fair workplace investigation starts with an investigation plan. Before anyone is interviewed, the plan should record what is being investigated and what is not, who will investigate, who will make decisions on the findings, what evidence sources exist, how confidentiality will be handled, and what support will be offered to the individuals involved. The scope should be proportionate: a single disputed comment does not need the same machinery as a pattern of alleged sexual harassment.
Two planning decisions matter more than the rest. The first is separating the investigator from the decision-maker, so the person who makes findings of fact is not the person who decides on disciplinary action. The second is choosing an investigator who is impartial and is seen to be impartial, with no conflict of interest and no stake in the outcome. Impartiality that cannot be demonstrated is worth very little when the process is tested later. Where the complaint has only just arrived and the business needs the intake stage handled quickly and cleanly, a structured workplace complaint response sits before the investigation proper and often determines whether one is needed.
Preserve the evidence early
Part of the investigation plan is an early sweep of the evidence that already exists, before memories are overwritten and files are tidied up. Emails, messages, rosters, CCTV, access records and system logs should be identified and preserved at the planning stage, because some of it will not survive routine retention cycles, and because knowing what documentary evidence exists shapes who needs to be interviewed at all.
The plan should also settle practical matters early:
- indicative dates for each stage, so the process keeps moving and drift is visible
- how interviews will be recorded, and where documents will be stored securely
- who the contact point is for the complainant and for the respondent
- what wellbeing support is available to everyone involved, including witnesses
- how the parties will be kept informed while the investigation is being conducted, since silence between stages is where anxiety and speculation grow
Step 2: Put the allegations in writing
An investigation cannot be fair if the person responding to it does not know precisely what is alleged. Each allegation should be written down as a specific claim of conduct: what is said to have happened, when, where, and who was present. "Inappropriate behaviour towards colleagues" is not an allegation. "On 14 March, in the site office, you are alleged to have said the following to a junior employee" is.
The Fair Work Commission's unfair dismissals benchbook makes the underlying principle plain. Where conduct later founds a dismissal, the employee must be notified of the reason in explicit, plain and clear terms, and before any decision is made. Framing allegations with that level of particularity at the investigation stage protects everyone: the respondent can actually answer the claim, the investigator can test it against evidence, and the eventual findings map onto something concrete. If new allegations emerge mid-process, they are added in writing and put to the respondent the same way, never folded silently into the final report.
Step 3: Decide interim measures
Interim measures protect people and evidence while the investigation runs. They are administrative and protective, never punitive, and they should never signal that an outcome has been decided. Options include adjusting reporting lines, moving one party to alternative duties, changing rosters or work locations, or arranging remote work.
Suspension is the strongest measure and should be treated as a last resort after less restrictive alternatives have been considered. Where it is used, suspension on full pay is the neutral form. Queensland's public sector suspension directive puts the general principle well: suspension is an administrative action taken for administrative necessity, not a form of discipline. In the private sector the power to suspend rests on the employment contract and general law, so checking the contractual basis before acting is part of the planning work.
Confidentiality directions and their limits
Employers routinely direct participants to keep the investigation confidential, and there are good reasons to: protecting the integrity of the investigation, protecting witnesses, and containing rumour. But a direction must be both lawful and reasonable. In one Fair Work Commission decision, a direction that an employee treat an investigation as confidential was found lawful but unreasonable in the circumstances, because it effectively stopped her consulting her partner for advice and emotional support, and the dismissal that followed partly for breaching it was unfair.
The practical guidance level is this: explain the purpose of confidentiality, keep the direction proportionate and time-limited, allow the parties to speak to support people and advisers, and accept that no direction can override statutory rights to seek advice or raise complaints with authorities. Blanket "tell no one" instructions are the version that fails.
Step 4: Interview the complainant, the respondent and the witnesses
Interviews are where many investigations are won or lost. The usual sequence is the complainant first, to confirm the allegations and identify evidence and witnesses, then the respondent, then witnesses who can speak to specific disputed facts. Every interview should open the same way: who the investigator is, what the investigation process is, what confidentiality means here, and what happens next.
Good interview practice is unglamorous and decisive:
- ask open questions and let people answer; leading questions contaminate accounts
- put the specific allegation, not a summary of it, to the person responding
- take contemporaneous notes and have interviewees review and sign their statements
- interview witnesses about facts they observed, not opinions about the parties
- keep interviews respectful and factual; this subject matter is hard enough for the people involved without theatre
The record of each interview matters as much as the interview itself. Whether the investigator works from typed notes, a signed statement or an agreed transcript, the account should be captured while it is fresh, put back to the interviewee for confirmation, and stored with the rest of the evidence. Months later, when a decision is challenged, the contemporaneous record is often the only thing standing between a defensible finding and a contest of recollections about what was said in the room.
Support persons
Anyone interviewed should be allowed to bring a support person, and scheduling should reasonably accommodate that choice. The legal frame is worth stating precisely, because it is often misquoted. In unfair dismissal matters the Commission considers whether an employer unreasonably refused a support person in discussions relating to dismissal. There is no positive obligation to offer one; the factor bites when an employee asks and the employer unreasonably says no. A support person supports; they do not advocate or answer on the person's behalf. Allowing one costs the process nothing and protects it considerably.
A genuine opportunity to respond
The respondent must get a real chance to answer each allegation before findings are made. The benchbook's standard is common sense applied fairly: no particular formality is required, but going through the motions when the outcome is already decided is not an opportunity to respond. That means giving the respondent the allegations in advance, reasonable time to prepare, the chance to name their own witnesses and evidence, and a follow-up opportunity if significant new material emerges after their interview.
Step 5: Weigh the evidence on the balance of probabilities
The standard of proof in a workplace investigation is the civil standard, the balance of probabilities: is it more likely than not that the conduct occurred? For serious allegations, the principle from Briginshaw v Briginshaw is regularly cited and regularly misstated. It does not raise the standard of proof. It says that the strength of evidence needed to reach reasonable satisfaction varies with the gravity of what is alleged, and that satisfaction should not rest on inexact proofs, indefinite testimony or indirect inferences. A finding that will end a career needs clearer evidence than a finding about a missed procedure, but both are decided on the same balance.
Weighing evidence means all of it, including the material that cuts against the complaint. Where accounts conflict, the investigator looks for corroboration, contemporaneous records, consistency over time, opportunity and inherent plausibility. "He said, she said" is not a dead end; it is a credibility assessment, done carefully and recorded honestly. An impartial investigator also resists the pull of the first coherent story, which is a real force in every contested matter.
Step 6: Make findings of fact
Findings are made allegation by allegation. Each is substantiated, not substantiated, or, where the evidence genuinely cannot resolve it, unable to be determined. The finding states the conclusion and the reasoning: what evidence was accepted, what was rejected, and why. Reasons are what make findings defensible later, whether to a court, a tribunal or the parties themselves.
Findings of fact are about facts. Whether substantiated conduct breaches a policy is usually part of the investigator's task; what should happen to the respondent as a result is not. Keeping findings separate from disciplinary action preserves the decision-maker's role and keeps the investigation clean.
State the finding plainly
Resist the temptation to soften findings into ambiguity. "There may have been some miscommunication" is not a finding; it is an evasion that leaves the complainant unheard, the respondent under a cloud, and the organisation with nothing it can act on. If the evidence supports a conclusion, state it. If it genuinely does not, say that plainly and explain what was missing.
Step 7: Report, and act on the outcome
The investigation report is the record the organisation will rely on. A sound report sets out the scope and allegations, the process followed, the evidence gathered, the findings on each allegation with reasons, and any observations about process or policy that surfaced along the way. It goes to the decision-maker, and access beyond that is controlled; a copy of the investigation report is not an all-staff document.
Then the organisation has to act. The decision-maker decides outcomes on the findings, which may mean disciplinary action, training, policy change, workplace adjustments or repairing working relationships. Both the complainant and the respondent should be told the outcome at an appropriate level of detail, promptly, and so should any other parties involved who were directly affected. If disciplinary action may follow for the respondent, procedural fairness continues: the findings and proposed action are put to them for response before the final decision. An investigation that ends in silence undoes much of the good the process did.
Where employers get this wrong
Very few contested investigations fail because the employer reached the wrong conclusion on the evidence. They fail because the process that produced the conclusion could not withstand scrutiny, and by the time that becomes apparent, in a conciliation conference or a hearing room, it is too late to repair. The recurring failures are procedural, and they repeat across industries:
- deciding the outcome first and running the process as decoration
- allegations so vague the respondent cannot meaningfully answer them
- drip-feeding new allegations without ever putting them in writing
- an investigator with a conflict of interest, or one who reports to a party
- refusing a requested support person, or refusing to move an interview so one can attend
- blanket confidentiality directions that isolate the very people under the most strain
- long unexplained gaps that let witness memories decay and signal indifference
- findings that quietly wander beyond the documented scope
- treating the findings and the sanction as a single decision made by a single person
None of these requires bad faith. They happen in businesses that started the workplace investigation with good intentions and no structure, which is precisely why the structure matters. Getting the process right also protects the working relationships that have to survive it, and a workplace culture where people trust that complaints are handled properly is built one competent investigation at a time.
The investigation is itself a psychosocial risk
There is a work health and safety dimension to all of this. Safe Work Australia's model code of practice on managing psychosocial hazards at work lists poor organisational justice, meaning inconsistent, unfair or inequitable management decisions and poor procedural justice, among the hazards employers must manage. The code expects processes for handling reports and complaints to be fair, objective, timely, impartial and procedurally fair to all parties. In plain terms, a badly run investigation is not just a legal risk; it is a hazard to the complainant, the respondent and the witnesses, and a fair process is the control. Steps taken to ensure the investigation is timely, impartial and properly communicated do real work in protecting the work environment while the matter is unresolved. The broader duty is covered in the Brookvale HR Solutions article on psychosocial safety obligations for employers.
When to bring in an independent investigator
Some matters should not be investigated internally, and recognising that early is a mark of judgment rather than weakness. Conducting a workplace investigation into a matter you are too close to is how a manageable problem becomes a contested one. The considerations that point to an independent workplace investigation include:
- a real or perceived conflict of interest anywhere in the internal option
- a respondent senior enough that no internal investigator can realistically test their account
- allegations serious enough to carry potential criminality, where coordination with police may be needed before anything else happens
- a realistic prospect of litigation, where the process will be scrutinised line by line
- allegations, such as sexual harassment, that call for specialist interviewing skills the business does not hold in-house
Public sector guidance formalises several of these factors, including specialist skills and conflict of interest; the seniority and litigation factors are professional judgment, applied case by case. The test is simple to state: if a reasonable observer would doubt the process because of who ran it, the finding will not hold, however careful the work was.
When a complaint is too serious, too senior or too close to home to investigate internally, businesses engage Brookvale HR Solutions for independent workplace investigations, conducted personally by Daniel Holbrook, who brings a former Military Police investigator's discipline and a Cert IV in Government Investigations to the interviewing, evidence-handling and findings work described in this guide. Call Daniel on 1300 23 44 23 to talk through whether independence is what the matter needs.
