9U.K.An authorised person may at any reasonable time require a person making such a supply as is referred to in section 23(1) or any person acting on his behalf—
(a)to open any gaming machine, within the meaning of that section; and
(b)to carry out any other operation which may be necessary to enable the authorised person to ascertain the amount which, in accordance with subsection (2) of that section, is to be taken as the value of supplies made in the circumstances mentioned in subsection (1) of that section in any period.