Whenever a request is made which involves access to records described in paragraph (g) of Sec. 212.41 and the investigation or proceedings involves a possible violation of criminal law; and there is reason to believe that the subject of the investigation or proceeding is not aware of its pendency, and disclosure of the existence of the records could reasonably be expected to interfere with enforcement proceedings, the Agency may, during only such time as that circumstances continues, treat the records as not subject to the requirements of 5 U.S.C. 552 and this subpart.