In any situation where the Administrator has reason to believe that any veterinarian accredited under the provisions of parts 160 and 161 of this subchapter has knowingly violated the Animal Health Protection Act (7 U.S.C. 8301 et seq.), the Administrator may summarily suspend the accreditation of such veterinarian pending final determination in either a suspension or revocation proceeding, effective upon oral or written notification, whichever is earlier. In the event of oral notification, a written confirmation thereof shall be given to such veterinarian as promptly as circumstances permit.