Police have issued an amber alert for a missing three-year-old B.C. boy, and say he may have been abducted by a convicted criminal.

Kienan Hebert of Sparwood, B.C. is believed to have left his family home off Highway 43 some time overnight. He was discovered missing at 8:30 a.m.

An amber alert was issued late Tuesday afternoon. RCMP say the little boy was abducted by 46-year-old Randall Peter Hopley, who drives a 1987 brown Toyota Camry with the B.C. licence plate 098RAL.

Hopley has previous convictions for sexual assault, assault, theft and break and enter. He was charged with abduction of a child and unlawful confinement in 2008, but those charges were later dropped.

Newspaper reports say that one of Hopley's more than 11 convictions for breaking and entering stems from a case in which he walked into an Alberta couple's vacation cabin, changed their padlocks and squatted for some time.

He was found by police trying to escape the property. When they searched the cabin, officers discovered sexual paraphernalia and a trove of stolen goods.

Police say that Hopley and Hebert have no previous relationship. Hopley is white, 5-10 tall and 147 lbs. and has brown hair, hazel eyes and a birthmark along his hairline.

Hebert has red hair, is believed to be wearing Scooby Doo boxer shorts and could be carrying up to three blankets with him.

"There's a history that Kienan does sleepwalk, but in past incidents, he's never exited the house," RCMP Cpl. Dan Moskaluk said.

RCMP officers started a search effort including an air services helicopter and a search dog unit, but have not found any sign of the boy.

Anyone with information on Hebert's or Hopley's whereabouts is asked to call 911 immediately.

With files from The Canadian Press