You must respond to any claimant's request for information on a comparator's pay and benefits within eight weeks: if you fail to do so, the Tribunal can order disclosure, or failing that, draw adverse conclusions. In responding, however, you need to balance the claimant's right to enough information to pursue her claim, with the comparator's right to privacy, under both the Data Protection Act and the implied duty of trust and confidence owed by an employer to an employee. This is a complex area, and you will need expert legal guidance.