Except as provided in this section, the Board administers and enforces the Interlocks Act with respect to state member banks, bank holding companies, and affiliates of either, and may refer any case of a prohibited interlocking relationship involving these entities to the Attorney General of the United States to enforce compliance with the Interlocks Act and this part. If an affiliate of a state member bank or a bank holding company is subject to the primary regulation of another Federal depository organization supervisory agency, then the Board does not administer and enforce the Interlocks Act with respect to that affiliate.