No prosecution for an offence under these Regulations may begin after the expiry of three years from the commission of the offence or 1 year from the date on which evidence sufficient in the opinion of the prosecutor to warrant proceedings came to the knowledge of the prosecutor, whichever is the earlier.

For the purposes of this regulation, a certificate signed by or on behalf of the prosecutor and stating the date on which evidence sufficient in the prosecutor’s opinion to warrant the proceedings came to the knowledge of the prosecutor, will be conclusive evidence of that fact.

A certificate stating that matter and purporting to be so signed will be deemed to be so signed unless the contrary is proved.