Skip to main content



Call us today for a free initial consultation on 0333 772 0611

Investigating disciplinary allegations

Published 23 October 2023

The importance of a disciplinary investigation cannot be underestimated as a case can fail or succeed on the strength of it.

It is a process that should aim to establish the facts in relation to any claim or suspicion of wrongdoing by an employee, and it should seek to collect all of the relevant evidence and details.

Investigations are covered by the ACAS Code of Practice on disciplinary and grievance procedures, which is the minimum an employer must follow[1 CITED 23.10.23]

In any claim for unfair dismissal, the manner in which an investigation was conducted can prove pivotal.[2 CITED 23.10.23]

This proved to be significant in a recent judgement in which a teacher was awarded almost £45,000 after being sacked over sex assault claims that pupils later said had been made up ‘for fun’[3 CITED 23.10.23]

The maths and computing teacher at an all-girls grammar school, was sacked after pupils said he had assaulted them by touching their thighs and massaging their shoulders.

Following the allegations, he was suspended from the school despite some older pupils later claiming the girls had told them they fabricated everything ‘because it was fun’.

He was arrested and dismissed for ‘gross misconduct’, an employment tribunal heard. His appeal against his sacking was then rejected, despite the police dropping the charges.

However, he has been awarded £44,868 – his annual salary – after the tribunal ruled the school had carried out a ‘wholly inadequate’ investigation.

Without carrying out a thorough and fair investigation, an employer is unlikely to be able to make what can be considered a reasonable and informed decision about an employee’s conduct and the appropriate sanction.

When dismissing an employee, an employer must reasonably believe the individual is guilty of misconduct and at the time it held that belief, it must have carried out as much investigation as was reasonable.

A  full and objective investigation is the foundation of any fair disciplinary process.

Here we take a closer look at four key steps in conducting a thorough and fair disciplinary investigation.

Step 1. When to investigate

Any allegation made against an employee should always be carefully considered, but not every single one will require investigation.

Different situations will require different approaches. Some possible situations in which an employer may not need to investigate are: if an allegation is very minor or trivial and does not impact on the employee’s performance or reputation; the claim is clearly false or malicious with no evidence to support it or reason to believe it; or if the matter has been investigated and resolved previously.

If ever an employer is unsure  about whether or not to investigate, it should always seek expert HR or legal advice.

Situations in which an employer should investigate an allegation include:

  • If an accusation is serious or complex and can lead to disciplinary action or dismissal if it is found to be proven.
  • Tangible or credible evidence is available to support the allegation and there are witnesses and a reasonable suspicion that the misconduct or wrongdoing has occurred.
  • What is alleged against an employee amounts to a breach of policy or procedure, or could be a criminal act.
  • There is potential for the allegation to harm the reputation or performance of the employee, impact on colleagues or the employer.
  • The claim raises legitimate concerns about the health, safety or welfare of the employee, other members of staff or the public.


Step 2. Getting ready to conduct an investigation

Appointing an appropriate investigator who is trained to conduct the process is important as it can help to ensure the investigation if fair and impartial. The investigator should have no involvement in the case.

An objective investigator can ensure that everyone is treated fairly and that there is no bias or pre-judgment in the process. It can also help to maintain trust and confidence between an employer and its employee.

Preparation for an investigation is key. Employers are advised to draw up an investigation plan, which can include: what needs to be investigated; details of witnesses who need to be interviewed; available evidence such as emails, documents or CCTV; and relevant policies or guidelines to consider.

The plan can help to structure the investigation, make the process efficient and help to ensure the focus is on what exactly needs to be done to establish all of the facts of a case. ACAS provide a helpful investigation plan template for employers [4 CITED 23.10.23]

The employee under investigation should be informed of it as soon as possible. In exceptional  circumstances an employer may delay telling the individual, especially if there is a genuine risk they may interfere with the investigation or influence witnesses.

Where an employee is made aware they are under investigation, they should be told why it is happening and what it will involve. The news can be a shock to any member of staff, regardless of their position, so an employer needs to consider what support the individual may need.

If a decision is taken to investigate, then suspending a worker should not be a knee-jerk reaction[5 CITED 23.10.23].

Each case should be carefully considered to determine if instructing the employee to stay away from work is appropriate, as suspension will only be needed in some situations. Alternatives to suspension should always be reasonably contemplated.


Step 3. Conducting the investigation

The investigation should be fair and objective and approached with an open mind. The aim should be to gather as much information as possible to get a balanced view of the facts. Evidence that supports both the allegation and the employee’s case should be sought.

The process should be conducted and concluded without unreasonable delay. A disciplinary policy will often contain a timescale for investigations, which can ensure the investigating manager is aware of what is expected of them and the employee is conscious of how long the process should take.

In serious or complex cases extra time may be needed to conclude a thorough investigation. If this is the case any delay should be explained to all parties involved in the matter.

Working to the investigation plan should ensure that all relevant evidence and information is gathered.

Witnesses should be interviewed and re-interviewed if necessary and statements taken and they should be signed and dated by any individual who can aid the investigation.

Holding an investigation meeting with the employee can ensure they get an opportunity to provide their version of events before a decision is taken about what action will be taken next.

If an investigation meeting is held with the employee, it is good practice to give them advance notice of it and time to prepare.

An employee has no right to be accompanied at an investigation meeting, although some disciplinary policies will allow it. If an employee asks to be allowed to be accompanied at the meeting, the request should be considered.

It is not unusual for an employee under investigation to become unwell and feel unable to attend an investigation meeting. They should be given every opportunity to attend the meeting. If the employee is repeatedly unable or unwilling to do so, then seek expert HR or legal advice about how best to proceed.


Step 4. At the end of the investigation

The evidence gathered should be assessed and if more information is needed it should be sought, which can include re-interviewing the employee facing an allegation.

An investigation report that details the findings and makes recommendations about the appropriate action to take should be produced.

There are a range of potential investigation outcomes, with the two main ones being no further action is required or that the matter should be considered at a formal disciplinary hearing.

Alternative conclusions may be that mediation, counselling or another form of support is appropriate for those implicated in the investigation

A reputation built on success

For employment law advice or if you are affected or want information and support by any of the issues in this article please give us a call. 

Castle Membership

Contact Us