Section 72: Proceedings under this Part may be commenced–

(a) if the offence alleged has involved the doing of an act, within 3 years after the Commissioner-General has become aware of the doing of the act; (b) if the offence alleged has involved the failure to do an act, within 3 years after the Commissioner-General has become aware of such failure; or (c) if the offence alleged has involved the nondisclosure or incorrect disclosure by a person of information relating to that person’s liability to GST for a tax period, within 6 years after the person’s correct liability to GST has become final for that tax period.