Costs of investigation of application
4.—(1)  The costs of such investigations and inquiries as may be required under section 46 of the Act shall be borne by the applicant.
(2)  The Authority may, from time to time, give a written notice to the applicant of the estimated costs of investigation and require the applicant to pay such estimated costs to the Authority within such period as may be specified in the notice.
(3)  At the conclusion of the investigation into the application or if the application is withdrawn, the Authority shall certify the actual costs of the investigation, and shall ––
(a)where the actual costs of investigation are lower than the amount paid under paragraph (2), refund the excess without interest to the applicant; or
(b)where the actual costs of investigation are higher than the amount paid under paragraph (2), by a written notice, require the applicant to reimburse the Authority the excess within such period as may be specified in the notice.