My question is:

My teacher said that a person can apply to have the conviction expunged from his record in the USA. It means that he would apply to the court in the USA where it occurred. If expunged, the conviction would no longer count against him for admissibility purposes, and he would be admissible to Canada.

Please explain what is the regulation/law/provision of Immigration law of Canada stipulates that "the conviction expunged from the criminal record in the USA would be accepted for Rehabilitation in Canada".

Thanks