What was initially believed to have been a body found off a major north Queensland road has turned out to be a "life-like replica doll", police say.

A crime scene was declared after officers were called to a trail off the Bruce Highway, south of Bowen, about 7am on Friday.

Forensic police began investigations into what had been reported as a "body wrapped in a blanket" but later concluded it was a "life-like replica doll of a human".

"Officers will continue investigations into the origins of the doll," police said in a statement.

The crime scene has since been disbanded.