Authorities said they went to check out a report of possible human remains on a sunken boat in the waters off Key West and discovered it was a fake skeleton.

A sponge fisherman called the Monroe County Sheriff’s Office at 1 a.m. Monday and reported that he saw what looked like “a human torso sitting on a captain’s chair about 3 feet underwater,” the sheriff’s office said on its blog.

Detective Manny Cuervo got a ride from the Fish and Wildlife Conservation Commission on Monday to the area, about 200 yards offshore of Archer Key – several miles west of Key West – and a FWC officer retrieved the chair and the attached “remains” from the water, the sheriff’s office said.

Once it was on board, they realized that it was really part of a plastic skeleton that someone had attached to the captain’s chair and put underwater. A long-sunken boat was nearby.

“It looks pretty real,” Cuervo said, “but if it was real, the skeleton would have fallen apart long before it had time to accumulate all the algae that was on it.”

“We removed it from the water so we don’t get any more calls about it in the future,” he added.

Monroe County Sheriff’s Office spokeswoman Becky Herrin said this is probably the first time they found a fake skeleton.

A few years ago they received a report of bodies in the water, “and when we went out to the boat we found out they were mannequins, so that’s kind of similar,” she said.