50.—(1) Where the immediate employer of any worker is himself in the employment of some other person and the worker is employed on the premises of that other person, that other person shall for the purposes of this Part be deemed to be the employer of the worker jointly with the immediate employer.

(2) Where an employer is charged with an offence under any section or subsection contained in this Part, he shall be entitled, upon information duly laid by him and on giving to the prosecution not less than three days’ notice of his intention, to have any other person to whose act or default he alleges that the offence was due brought before the court hearing the charge at the time appointed for the hearing of the charge, and thereupon the following provisions shall have effect—

(a) if, after the commission of the offence has been proved, the employer proves that the offence was due to the act or the default of that other person, that other person may be convicted of the offence,

(b) if the employer further proves that he has used all due diligence to secure that this Part and any relevant regulation or order made thereunder were complied with, he shall be acquitted of the offence.

(3) Where a defendant seeks to avail himself of subsection (2) of this section—

(a) the prosecution, as well as the person whom the defendant charges with the offence, shall have the right to cross-examine him, if he gives evidence, and any witnesses called by him in support of his pleas and to call rebutting evidence,

(b) the court hearing the charge may make such order as it thinks fit for the payment of costs by any party to the proceedings to any other party thereto.

(4) Where—

(a) it appears to an inspector that an offence has been committed in respect of which proceedings might be taken under this Part against an employer, and

(b) the inspector is reasonably satisfied that the offence of which complaint is made was due to an act or default of some other person, and that the employer could establish a defence under subsection (2) of this section,

the following provisions shall have effect—

(i) the inspector may cause proceedings to be taken against that other person without first causing proceedings to be taken against the employer,

(ii) if such proceedings are so taken, that other person may therein be charged with and, on proof that the offence was due to his act or default, be convicted of the offence with which the employer might have been charged.