At first glance, one might think the answer to this question was rather obvious, in that the employee raising the grievance is going to want to see that the investigation has been done thoroughly and fairly in order to be able to accept that the employer is following the correct processes based on the evidence. Indeed, if you didn’t disclose these papers to the employee, it is likely to foster distress and further antagonise what may already be the steps on the way to a breakdown in trust and confidence between the parties.
Having said that, are there circumstances in which you can decline to show the employee parts of the evidence? It is worth noting that the ACAS Code of Practice in relation to grievance procedures does not grant a specific “right” to the employee to see witness statements or any evidence that is part of an investigation.
The employer is likely to be having to balance the rights of the employee against the rights of others who have also been named in the report, and to whom it may also owe duties such as confidentiality, if that were the only basis on which it could obtain evidence.
The ACAS Guide to Conducting Workplace Investigations states “if an individual wishes to see a report they have been named in, they have got a right to see any parts of the report that contains information about them or that is reliant on information they have provided”. That makes sense because they may want to correct a mistake that you have made in quoting them or if they disagree with an interpretation that has been made by the investigator. The ACAS Guidance goes onto say “however, they should not be allowed to see private information belonging to other individuals”. Thus, you would not necessarily be disclosing to them the entire report. It may be that in sensitive cases, where perhaps co-operation in an investigation has only been able to be obtained by witnesses being promised anonymity, certain parts of the report/statements would have to be redacted. In such circumstances, it may be that you change the names and other identifying information to, for example, numbers or letters, say witness B etc.
Ultimately, it is down to the employer to decide what the best thing to do is in each case and we would recommend that the rationale for acting in a particular way is recorded at the relevant time, so that if it is challenged later, at appeal or through the Tribunal, there is a record of the decision-making process.