Where you require an employee to sign a witness confidentiality agreement and undertaking, it's only right that you explain the seriousness of the document to them. This should include the likely consequences if they breach it. Our covering letter sets out your expectations and the sanctions you may impose if they're not met.
Explaining the position
Taking part in a disciplinary investigation is a serious matter. As a result, you should ask all witnesses involved in the proceedings to sign a confidentiality agreement and undertaking. Doing this ensures they're under no illusions as to what’s expected of them; for example, that they:
This will also ensure that the confidentiality of the employee(s) at the centre of the allegations is protected.
Sign the document
Our Letter Enclosing Witness Confidentiality Agreement and Undertaking draws the terms of the document to their attention. It also points out the implications of any breaches on their part. If this occurs, there's no reason why you can't treat it as gross misconduct, i.e. it could result in their dismissal. This must be spelled out to the employee.
Finally, on a practical point, always enclose two copies of the witness confidentiality agreement and undertaking. The employee should retain one; the other must be signed and returned to you for your records. It's unlikely they'll have any issues with signing this document, but if they do have queries, deal with them promptly.