Follow this nine-step guide for a clear framework to carrying out fair, thorough and defensible workplace investigations.
Before an investigation can begin, you need to clearly understand what concern has been raised. This is often captured in a ‘Terms of Reference’ document which records what has been alleged, who raised the concern, when it was reported, where the alleged incident occurred and what outcomes have been requested.
You or the person who instructed you to investigate should consider whether urgent action is required. For example:
At this stage, you should also consider whether you are the appropriate person to conduct the investigation. If you are directly involved in the matter or may be a witness, an alternative investigator should be appointed. Read our detailed guide about who should investigate.
A clear investigation plan helps demonstrate that the process is fair, reasonable and properly resourced. Before gathering evidence, add to the Terms of Reference what you already know about:
It is important that the investigator remains separate from anyone who may later chair a disciplinary hearing, grievance hearing or appeal.
Identify which organisational procedures apply to the matter and ensure you understand the requirements of any relevant policies so you can follow them throughout the investigation. Common policies referred to include disciplinary and grievance, bullying and harassment policies, Whistleblowing procedures, equality and diversity policies and absence management procedures.
Failure to follow contractual procedures may expose the organisation to additional complaints or legal challenges.
Evidence gathering is often the most time-consuming stage of the investigation. The objective is to identify all relevant information, not simply evidence that supports a particular conclusion. Evidence may include witness statements; emails and correspondence; attendance records; performance records; policies and procedures; CCTV footage; telephone records and electronic communications.
Act promptly to preserve evidence wherever possible, particularly where records may be deleted or overwritten.
Most workplace investigations involve interviews. This step is often done at the same time as step four. Typically, this will include:
The person who raised the complaint, allegation or grievance can provide important information about the events being investigated.
The employee being investigated, who should be given an opportunity to explain their version of events and respond to concerns that have been raised.
Witnesses may provide first-hand information, corroborate evidence, or offer valuable context.
Some witnesses may be reluctant to participate. Taking time to explain the process, reassure them about confidentiality, and address concerns often improves engagement. The purpose of every interview is to establish facts, not to decide outcomes. Read our blog about how to engage with a reluctant witness.
Investigations should be conducted as confidentially as possible. Information should only be shared with individuals who have a legitimate need to know. Investigators should conduct interviews privately, store records securely, limit access to investigation documents and avoid discussing the matter unnecessarily.
While confidentiality is important, employees should understand that complete confidentiality cannot always be guaranteed, particularly if information is later required during appeals or legal proceedings. Jump to more about confidentiality.
Once the evidence has been gathered, it must be reviewed objectively. Consider:
Workplace investigations are generally assessed on the balance of probabilities. This means determining what is more likely than not to have happened based on the evidence available. Investigators should remain impartial and avoid assumptions throughout the process.
The investigation report should provide a clear and objective summary of the issues investigated, evidence gathered, interviews conducted, findings of fact and any recommendations where appropriate.
The report should distinguish clearly between facts, allegations, opinions and conclusions. A well-written report enables the deciding officer to make informed decisions and demonstrates that a fair process has been followed – read our how to write an investigation report guide.
Once the report is complete, the report and appendices should be provided to the deciding officer. The investigator’s role is to establish the facts so decisions regarding outcomes should normally be made by a separate person, usually a more senior manager.
Depending on the findings, the organisation may decide on a variety of possible outcomes, for example, that no further action is required, informal action is appropriate, additional enquiries are needed, a formal hearing should take place and whether further support or intervention is required.
Read all about the pros and cons of internal and external investigators, including:
What is a workplace investigation?
How to conduct a workplace investigation
Who should investigate?
Suspensions during investigations
Interviewing witnesses
Confidentiality
Gathering evidence
Writing reports
Timescales
