The Oakland County Sheriff's Office says a woman at a bar in Waterford called on Wednesday to say she had information about a bomb threat involving the GM Plant in Orion Township.
The office said the caller claimed she had been talking to man at Shorties Bar who told her he was "more than frustrated" with the plant.
The woman said the man had told her he placed a bomb in the plant and that it was set to go off at 3 a.m.
The woman described the man she encountered as white with red hair.
Police said plant supervisors were notified and the plant was checked out - but nothing unusual was found.
Police are continuing to investigate the incident.