A person who is a prescribed employee for the purposes of Division 2 shall furnish to the Board, before the expiration of 3 months after the date on which he became an employee, or before such time as the Board in special circumstances allows, an authority in writing authorizing the Board to obtain such information from his previous employer or from any person administering the superannuation scheme applicable in relation to his previous employment as the Board considers necessary to enable it to make determinations under section 100C in respect of the person.