Skip to main content
« Back to Blog

What makes an investigation unreasonable?

This is a cross-posted article, originally written on the Pure Employment Law Website and has now been posted here. Please note the date on which this article was posted originally and that any information within may have changed. 

15 July 2019

Investigations are a particularly hot topic in employment law at the moment – as you may have seen in our recent articles about when you might need to appoint an external investigator, and how long an employer should wait before taking internal action where an employee is subject to a police investigation.

An investigation is a key part of any disciplinary or grievance process, and if the allegations are serious then it is especially important that the investigation stands up to scrutiny.

The recent case of S v Tesco Stores Limited involved an allegation of harassment. In light of the recent #MeToo and #Time’sUp movements, we are finding that more employees are coming forward with allegations, and also that employers are more aware than ever of the importance of taking such allegations seriously.

However, in the Tesco case, they were found to have unfairly dismissed an alleged harasser, because they failed to carry out a reasonable investigation. The case was heard by an Employment Tribunal in Scotland, however the same rules regarding reasonableness apply.

The background

The employee (S), was 39 and had worked for Tesco for 20 years. He was alleged to have sent inappropriate messages to a 17 year old colleague (E) on Facebook and also to have made inappropriate comments to her in person. The messages from S to E included:

  • “You’ve got 3 days to get your cute ass to the doctors”, when E was unwell
  • Inappropriate emojis
  • “I’m going to tickle you till you pee”
  • “You’re definitely overdue a tickle”

S was suspended, and an investigation was carried out. S attended an investigation meeting. The investigating officer concluded that there was a disciplinary case to answer and that a disciplinary hearing would be held. Following the disciplinary hearing, S was dismissed for gross misconduct. He appealed, but his appeal was unsuccessful. He then brought a claim for unfair dismissal in the Employment Tribunal.

What was wrong with the investigation?

The Tribunal criticised the investigating officer for not speaking to E personally, and also for not speaking to the two managers who had initially taken statements from E. This meant that there were a number of issues that had not been explored, such as the circumstances that had led to the statements being made and who had made the copies of the messages.

E had mentioned, in her statement, other individuals who could have given relevant evidence, but they were not spoken to. The Tribunal stressed the importance of understanding the context in this type of situation, as it is relevant in deciding whether the messages were conversations between friends, as S argued, or whether S was harassing E.

In addition, the disciplinary officer was criticised by the Tribunal for having “gone in to the disciplinary meeting with the belief that [S] was some sort of sexual predator”. The Tribunal found that this “coloured his approach to anything said by [S] and his representative and the way that the disciplinary hearing was conducted. It appeared … "that he had had no intention of listening to anything that [S] might say and did not approach the matter with an open mind”.

All of the managers involved were criticised by the Tribunal for not making any attempt to investigate the points raised by S at his investigation meeting, disciplinary hearing and appeal hearing, including: that he viewed the messages as a conversation between two adults, that Facebook Messenger provides a number of ways that someone can break off communication but E had not done so, and also that many of E’s responses could also be viewed as inappropriate too. S had given a different version of events in relation to two incidents that formed part of E’s complaint, but this was not investigated.

The Tribunal found that the appeal officer could have interviewed witnesses who should have been interviewed at an earlier stage but didn’t and that Tesco had still failed to carry out a proper investigation despite the fact that the appeal officer had persuaded S to agree that he didn’t want anyone else to be interviewed.

The Tribunal found that S had been unfairly dismissed and he was awarded just over £17,000 (after a 25% deduction for contributory fault.


Whilst it is of course very important to take allegations of harassment seriously, it is equally important not to jump to conclusions and to make sure that all decisions are based on a reasonable investigation. Using an experienced impartial investigator is a good idea, and in some situations it may be best for that to be someone from outside the organisation.