A body found Friday by employees of a Petaluma waste disposal center apparently was dumped there by a refuse truck, a sheriff's spokesman said.

The grim discovery at North Bay Corp. on Petaluma Boulevard South was reported at about 1:50 p.m., Lt. Tim Duke said.

Detectives believe the remains may be that of a homeless man who might have crawled into a recycling bin to escape the cold.

Workers sifting through a pile of refuse in a recycling bay uncovered the fully clothed body, Duke said.

Deputies identified him as a Sonoma County resident but would not release his name until his family could be notified.

The cause of death was not known.

Duke said it could have been an accidental death but investigators would not rule out the possibility of foul play.

The man had suffered facial injuries that could have come during transport, Duke said.

"We're tracking the routes of the trucks that dump here," Duke said.

He said one possibility is the man had used a recycling container as shelter. Overnight temperatures around Sonoma County this week have dropped below freezing.

Once inside, the man either died of hypothermia or fell asleep, Duke said. He may have become trapped when a truck picked up the container, Duke said.

"That's a theory we're working with right now," he said.

Early reports described the discovery at the regional transfer station as a "body dump." Duke said the investigation is ongoing.

Yellow police tape marked the investigation scene Friday afternoon at a large metal building with two open doors. Debris was piled high inside.

North Bay Corp. is part of the Ratto Group, the largest trash hauler in Sonoma County.