(a) Before referring a complaint to an administrative law judge under section 201 of this part, the Commission may conduct investigation using an exchange of letters, interrogatories, fact-finding conferences, interviews, on-site visits or other fact-finding methods that address the matters at issue.

(b) During an investigation of a complaint under this part, the Commission shall have the authority to sign and issue a subpoena requiring the attendance and testimony of witnesses, the production of evidence and access to evidence for the purposes of examination and the right to copy. The subpoena procedures contained in 29 CFR 1601.16 shall apply to subpoenas issued pursuant to this section.