Managing workplace investigations: common questions answered

In recent years, there has been a marked increase in the number of workplace investigations, a trend that shows no sign of abating. This rise is largely attributable to the growing complexity of grievances faced by employers within an ever-changing and evolving work environment. Against this backdrop, it is essential that workplace investigations are conducted thoroughly, fairly and efficiently as failure to do so may result in a flawed process, exposing employers to the risk of potential litigation.

In this article we take a look at some of the most frequently asked client questions when it comes to handling a workplace investigation and how best to approach these challenging situations.

1. What should an employer do if an employee raises concerns but does not wish to proceed with a formal complaint?

This arises often in practice and is difficult for employers as in most cases without a formal complaint it may not be possible to commence an investigation. However, employers can still support the employee by directing them to the appropriate policies/handbook, company supports such as EAP and reminding them that there are procedures in place to help them resolve workplace issues. This might ultimately lead to a formal complaint being made by the employee. Employers are also on notice of the issues raised and are advised to consider if the employee is in immediate danger or at risk.

2. How to determine which policy applies to a particular complaint?

If there is any ambiguity surrounding an employee’s complaint, it can be helpful to meet with the employee to discuss their issues in further detail. This will assist the Company and the employee in identifying the most appropriate policy bearing in mind that in some instances one or more policies could potentially apply. Employers also need to be mindful that complaints that involve broader issues, such as breaches of legal obligations or health and safety concerns, may constitute a protected disclosures or whistleblowing complaint, which require different handling and offer specific protections.

3. Are Terms of Reference strictly necessary for an investigation?

While certain Codes of Practice including the Code of Practice for Employers and Employees on the Prevention and Resolution of Bullying at Work provide that an investigation should be governed by Terms of Reference, it is not strictly required from a legal perspective for all workplace investigations.  In practice, Terms of Reference are however recommended as they can help put structure on an investigation, foster a sense of fairness, manage parties’ expectations and even prevent the investigation from broadening in scope. Where there are clear Terms of Reference there can be little dispute over matters such as timings and who gets copies of what documents where these are clearly outlined in the Terms of Reference. This can ultimately result in a time and cost saving exercise for employers saving the need to address such queries throughout the investigation process.

4. Who should conduct the investigation?

This depends on a number of factors including resources, practical experience, the size of the organisation and the type of complaints at issue.  In recent years we have seen a growing trend towards appointing an independent external investigator, particularly in cases involving senior employees, complex facts or sensitive issues. Investigations are notoriously time-consuming and so by appointing an external investigation an employer can ensure that it frees up some of its internal resources and ensures the investigation receives the necessary attention and focus. However, employers need to be mindful that appointing an external investigator does result in relinquishing control of the process to an external party and so choosing the right external investigator is key.

5. Does an investigator need to meet with all suggested witnesses?

Throughout an investigation, both the complainant and the respondent may propose multiple witnesses to the investigator. However, the decision as to who the investigator needs to meet as part of an investigation ultimately lies with the investigator and involves assessing whether the proposed witness is likely to have information that is material to the allegations under investigation. We advise employers to address this point within the Terms of Reference governing the investigation.  

6. How should an employer proceed if an employee goes on sick leave during an investigation?

The first step should be to refer the employee to occupational health to assess whether the employee is fit to participate in the investigation process. It is often the case that an employee may be unfit for work but fit to take part in meetings or interviews related to the investigation, even if they are not fit to return to their normal duties.

If occupational health advises that the employee is not fit to participate in the investigation, the employer should consider the circumstances on a case-by-case basis. If the period of incapacity is likely to be short, it may be reasonable to pause the investigation temporarily until they are fit to engage. However, if the employee is likely to remain unfit for a prolonged period, the employer may need to consider what steps, if any, can be taken in the employee’s absence e.g. interviewing witnesses or collating other relevant material.   

7. Is the complainant entitled to be informed of the outcome of a disciplinary process?

A complainant is generally only entitled to know of their outcome of their complaint or grievance and not the outcome of any subsequent disciplinary process.  A disciplinary process, the outcome, or any sanctions imposed on an employee are personal and confidential to the employee who is the subject of the process and generally should not be disclosed to the employee who originally raised the complaint.

8. Are there alternatives to conducting formal investigations?

There are plenty of alternative approaches that can be highly effective, particularly where the aim is to preserve or restore working relationships, such as mediation which is voluntary and confidential. Informal facilitated discussions is another option which is often overlooked and involves bringing the parties together to discuss the underlying issues and agree on a way forward. Such methods are often very effective in resolving interpersonal issues between employees in a manner that maintains working relationships.

For further information in relation to this topic, please contact Chris Ryan, senior associate, Aoife Clarke, senior associate or any member of the ALG Employment team.

Date published: 5 June 2025