18Where an officer finds gaming machines provided on any premises in such circumstances that a gaming machine licence is required so as to authorise them so to be provided and either—
(a)there is not produced to him on demand a valid gaming machine licence in respect of the premises, or
(b)such a licence is produced, but the officer is satisfied that, having regard to the number of machines on the premises and their description, there is or has been a contravention of section 24 of this Act in respect of the premises,
all gaming machines found on the premises shall be liable to forfeiture.