Investigations – How they can go wrong

Wednesday August 13, 2025

When you put a group of employees together in a team there will be, at times, fallings out. “Hell is other people” as the philosopher Jean-Paul Sartre pessimistically said!

If a falling out is serious enough, you will need to conduct a workplace investigation – one part of your disciplinary and grievance process.

For you, running an SME business, this could be time-consuming, costly and frustrating; even if you get it right. Any investigation is complex, requiring a technical procedure underpinned by the Acas code of practice on disciplinary and grievance procedures. “Full and fair” are of paramount importance in Acas’s eyes.

Failure to follow the Acas code can result in a penalty awarded at a subsequent employment tribunal being uplifted by as much as 25%.

In this blog, we will look at a fictional case study of a workplace investigation gone wrong; with expert tips to show how we would have intervened to do it correctly.

 

A workplace investigation in context

As we said, a workplace investigation is part of your disciplinary and grievance process. Before the investigation itself commences, you will have acknowledged the grievance in a timely manner and held a meeting to understand the issue fully. A disciplinary investigation on the other hand may be, for instance, that you suspect an employee of theft. After the investigation, a report will be produced for you to consider the next steps.

 

A case study of a workplace investigation gone wrong

Our fictional company, let’s call them Random Offices, employs 20 people. There is the managing director, a finance director and two line managers. There has been an accusation of bullying made by an employee against one of the line managers, and the company knows it will need to investigate. So what does it do?

 

Choosing the investigator

The managing director of Random Offices makes a crucial first mistake, choosing to appoint the other line manager as the investigator. The problem here is that they are well-known to be “good mates” with their colleague under investigation, often out after work with each other and with similar approaches to management. This flaws the investigation from the off as it will not be perceived as having the necessary impartiality.

Our advice: If Random Offices was an Advice Line client of ours, we would recommend that the person carrying out the investigation is clearly independent, and also will be separate from the person who decides upon any potential disciplinary action. For Random Offices, it may be more appropriate if the finance director carries out the investigation, leaving the managing director free to carry out any subsequent disciplinary action if appropriate.

It is also important, though, that the investigator has the necessary investigatory skills, including for the gathering of evidence, maintaining confidentiality and record keeping. If the two directors did not have the time or skill, we can offer to act as an expert, independent investigator.

 

Gathering the evidence

It is obvious that the accuser and accused in such a case may both be interviewed to get each side of the story. However, the Random Offices investigator leaves it there. No other members of staff are questioned formally and email communications are not reviewed.

Our advice: Gathering a broad evidence base as soon as possible is a hallmark of a good investigation. We would advise having a plan of who was involved directly, who witnessed the event. This allows you to identify key witnesses and interview them early on (so recollections do not fade).

Avoid leading and closed questions and ignore hearsay evidence. Statements from these interviews need to be written and signed. Make sure the interviewees understand how their testimony will be used. There are complicated rules regarding rights to be accompanied to disciplinary meetings, so these must be understood by the investigating officer.

Think beyond just what people say, and collect any more tangible evidence – digital or physical – that will help you come to a conclusion: emails, CCTV, damaged property etc., critically assessing each on its own merits.

 

Failing to document the investigation

The Random Offices line manager does not keep notes of his decision making processes and findings during the investigation, such as deciding who he interviews and how he interpreted the answers. This weakens the course of the investigation itself as it is all rather haphazard. It means that when he reports to the directors there are significant gaps which could be picked apart if disputed.

Our advice: They say that “if it is not down in writing it did not happen”, and at the very least an investigation will lose much of its credibility under scrutiny if it is not thoroughly documented.

We would urge that from the moment a complaint comes in, detailed notes are maintained which include the complaint and initial response, interview notes with statements, what evidence is gathered and its chain of custody, the comms sent to relevant stakeholders, the Investigation Officer’s assessment and rationale behind decision making as well as a concluding report.

 

Investigation services from The HR Dept

When a workplace investigation starts it will be employees under the microscope. But if the matter escalates afterwards, it will be your business and the investigation itself that becomes the focus – especially at an employment tribunal.

If an investigation needs to be performed within your business and you want to ensure it is done properly, with fairness and consistency, then ask us. We can provide advice throughout or make a trained, experienced investigator available to you to ensure it is done properly, whilst minimising the time you or senior staff need to spend on it.

Preventing People Problems

Subscribe to our monthly newsletter

Your enquiry will be sent to your most local office, based on the business post code you enter

Office Address: Office 213, The Innovation Centre, Festival Drive, Ebbw Vale , NP23 8XA | VAT Number: 307506912 | Registration Number: 11619814

Copyright © 2007 - 2019 The HR Dept Ltd. HR DEPT is a registered trademark belonging to The HR Dept Limited.