18.—(1) An employer shall keep such records as may be necessary to enable the Minister or an authorised officer to ascertain whether or not the provisions of this Act are being and have been complied with.

(2) Records kept under this section shall be retained by an employer for a period of not less than three years from the date on which they were made.

(3) An employer who contravenes subsection (1) or (2) shall be guilty of an offence and shall be liable on summary conviction to a fine not exceeding F29[€5,000 ].

(4) Where an employer fails to keep or retain records under this section the onus of proving that he has complied or is complying with this Act shall lie on him.