29 CFR § 2.22 - Production or disclosure prohibited unless approved by the appropriate Deputy Solicitor of Labor.

In terms of instructing an employee or former employee of the manner in which to respond to a demand, the Associate Solicitor, Regional Solicitor, or Associate Regional Solicitor, whichever is applicable, shall follow the instructions of the appropriate Deputy Solicitor of Labor. No employee or former employee of the Department of Labor shall, in response to a demand of a court or other authority, produce any material contained in the files of the Department or disclose any information relating to material contained in the files of the Department, or disclose any information or produce any material acquired as part of the performance of his official duties or because of his official status without approval of the appropriate Deputy Solicitor of Labor.