This part applies to investigations and investigational proceedings undertaken by the Secretary, or the Secretary's designee, pursuant to the following:

(a) The Interstate Land Sales Full Disclosure Act, 15 U.S.C. 1701 et seq.;

(b) The National Manufactured Housing Construction and Safety Standards Act of 1974, 42 U.S.C. 5401 et seq.; and

(c) The Real Estate Settlement Procedures Act of 1974, 12 U.S.C. 2601 et seq.