Managing reluctant complainants: advice for investigators

Insight

24.02.2025

It is not uncommon for organisations to receive anonymous complaints about a staff member. Complaints may arrive via an unsigned letter or an anonymous email, potentially sent to multiple recipients. Concerns might also be raised through via staff surveys, culture audits or via anonymous posts online. In our experience, these complainants often request or expect action to be taken in response to their concerns. However, they may not understand that their anonymity can significantly limit an organisation’s ability to investigate or respond effectively.

If the anonymous complaint becomes known to the accused or more widely among the team, this can add further complexity. Not progressing an investigation due to anonymity concerns could leave the allegations “out there” and the accused could feel legitimately aggrieved if they do not have an opportunity to respond to damaging allegations. Doing nothing also risks a perception of the issue being minimised or “swept under the carpet”, which can be damaging for the complainants, the subject of the complaint, the wider organisation and workplace culture more broadly.

If allegations are specific and serious enough, organisations should try to investigate and engage with the complainants (where this is possible) to encourage them to come forward and participate in an investigation, and to do so on a named basis.

This blog offers practical tips for investigators working with reluctant complainants and navigating investigations where anonymity is not ultimately waived.

Investigators should reflect carefully on the express (or implicit) reasons why the complainant/s may not come forward and ask them to articulate their concerns. You may be able to address them.
Reassure the complainant about the purpose, scope, integrity and confidentiality of your investigation. Carefully drafted, empathetic and professional correspondence can enhance the complainant/s’ trust in the process. There is a balance to be struck here. Wording should not be heavy-handed or overly formal so that complainants feel intimidated. However, an overly casual or friendly style may not build trust in the process or could give the individual a false impression about what the investigation will be like.
Do not promise anonymity. For the reasons for this see our previous blog. However, reassurances that you will not reveal their name to the complainant without their consent and agreement could lead to a useful initial conversation where you can explore their concerns and discuss the basis on which they might be happy to engage in the process.
Investigators should make genuine and repeated attempts to engage the complainant and facilitate their engagement in the investigation. If a participant chooses not to engage in an investigation due to their desire for anonymity, it can significantly impact the investigation’s progress and outcome. The investigator will not be able to hear their accounts directly, ask clarificatory questions and assess their credibility. As mentioned below, this also prevents the subject of the complaints from fully understanding and responding to the allegations against them.
Keep a record of your efforts to engage with the complainants. You will need to set this out in your report.
Consider what your organisation policies say about anonymity to help ensure you are taking a consistent approach.
Also consider the ACAS Guide on Conducting workplace investigations. This says “an investigator should try to avoid anonymising witness statements whenever possible.” Anonymity should only apply in exceptional circumstances where the participant has a “genuine fear of reprisals”.
If you do decide to proceed with the investigation while maintaining the individual’s anonymity, be very careful in your preparation, questions, correspondence and your report to ensure that this is respected. Remember that people can be identified directly or indirectly. You could also tell the complainants which allegations you propose to put to the complainant (on an anonymous basis) and give them an opportunity to flag any concerns. If complaints have been made very widely/publicly, this may not be necessary.
In progressing the investigation, a key challenge will be ensuring fairness to the subject of the complaint. As a starting point, the subject of complaint must be able to understand and respond to the allegations made against them. Do you have enough detail to put the complaints to the accused? It is entirely legitimate for the accused to say that they are not able to properly defend themselves if they do not know who has made the complaint against them. However, as noted above, they may also value the opportunity to put forward their response and have that on record.
Can you corroborate the complainants or the accused accounts in other ways? Explore other witnesses you could speak to or documentary evidence you could seek (ensuring that in requesting this you preserve anonymity). This evidence could help you build a fuller picture and make factual findings.
Ensure you deal with the impact of anonymity in your report and think carefully about whether you have sufficient evidence (which has been fairly and properly tested) to make findings on the balance of probabilities.
Investigators should reflect on the reasons given for anonymity and attempt to assess their credibility, to the extent that this is possible. As new evidence arises, any decision regarding anonymity should be reviewed.