Updated

A high-risk sex offender being sought in Canada was allowed to enter the United States after authorities determined that he was a U.S. citizen and not subject to an extraditable warrant.

A U.S. law enforcement official said Friday that U.S. authorities were aware of a warning from Canada that Michael Sean Stanley might try to cross the border. But officials allowed Stanley through the border after reviewing his information in a biometric records check. The official spoke on condition of anonymity to address an ongoing law enforcement matter.

A spokeswoman for the Edmonton Police Service in Canada says authorities are now looking into the extradition process.

Stanley has a long history of sexual offences against women and children and has been missing since Oct. 1 when he cut off his electronic monitoring bracelet around the Alberta-Saskatchewan boundary.