; or (3) has testified, or is about to testify, in any inquiry or proceeding relating to any right provided under this subtitle. (c) Construction Nothing in this section shall be construed to state or imply that the scope of the activities prohibited by section 105 of the Family and Medical Leave Act of 1993 ( 29 U.S.C. 2615 ) is less than the scope of the activities prohibited by this section. 335. Enforcement authority (a) Investigative authority (1) In general To ensure compliance with the provisions of this subtitle, or any regulation or order issued under this subtitle, the Secretary shall have, subject to paragraph (3), the investigative authority provided under section 11(a) of the Fair Labor Standards Act of 1938 ( 29 U.S.C. 211(a) ), with respect to employers, covered direct care professionals, and other individuals affected by an employer. (2) Obligation to keep and preserve records An employer shall make, keep, and preserve records pertaining to compliance with this subtitle in accordance with section 11(c) of the Fair Labor Standards Act of 1938 ( 29 U.S.C. 211(c) ) and in accordance with regulations prescribed by the Secretary. (3) Required submissions generally limited to an annual basis The Secretary shall not require, under the authority of this subsection, an employer to submit to the Secretary any books or records more than once during any 12-month period, unless the Secretary has reasonable cause to believe there may exist a violation of this subtitle or any regulation or order issued pursuant to this subtitle, or is investigating a charge pursuant to subsection (c). (4) Subpoena authority For the purposes of any investigation provided for in this subsection, the Secretary shall have the subpoena authority provided for under section 9 of the Fair Labor Standards Act of 1938 ( 29 U.S.C. 209 ). (b) Civil action by covered direct care professionals or individuals (1) Right of action An action to recover the damages or equitable relief prescribed in paragraph (1) may be maintained against any