COEUR d'ALENE - An autopsy Wednesday concluded that a scuba diver's death a day earlier near The Coeur d'Alene Resort Golf Course was likely a drowning, authorities said.

Mike McCullough, 31, of Rexburg, Idaho, was found floating Tuesday in Lake Coeur d'Alene near the golf course's floating green, according to the Kootenai County Sheriff's Department.

The exact cause of death was unknown Tuesday.

McCullough was working for a contractor who gathers golf balls and other debris from the lake bottom in the area.

Investigators learned, after interviewing all witnesses, that when McCullough was found floating on the surface, he was wearing a dry suit, weight belt, buoyancy compensator and dive tank. He also had a large basket of golf balls fastened to his equipment.

The rescuers, in order to lift him into the boat, cut the tank, buoyancy compensator and the golf balls from him.

Tuesday evening, sheriff's divers returned to the scene in 12 feet of water and recovered all of the items that had been cut off the victim. Inspection of the equipment showed no air in the tank, according to the sheriff's department.

There were no indications of any other trauma or medical factors that contributed to his death, the sheriff's department said.

Tuesday was McCullough's first day of diving for contractor Bob Hamilton. McCullough had been certified to dive in Southern Idaho, but according to family members, he had not been diving since 2007.

The investigation is continuing, but initial results point to a tragic accident, the sheriff's department said.

A golf course employee noticed the man floating on the surface of the water just off the northeast corner of the floating green just before 4 p.m. Tuesday. Employees called 911 and pulled the man from the water and began CPR. The man was taken to Kootenai Medical Center where he was pronounced dead.