Whenever a person is charged with an offence in terms of this Act of failing to report the loss or theft of explosives and it is proved that such a person was, at the time, the licensed or authorised possessor of the explosives alleged to have been lost or stolen, proof that the person has failed to produce such explosives within seven days of the request of the inspector to do so, will, in the absence of evidence to the contrary which raises reasonable doubt, be sufficient evidence that the explosives have been lost or stolen.