The remarkably well-preserved body of a scuba diver who sank and vanished 17 years ago in Lake Tahoe has been found on an underwater ledge deep in the mountain lake, authorities said on Tuesday.

The body of Donald Christopher Widecker, 44, was pulled from Lake Tahoe on July 27, four days after a group of divers stumbled across it while exploring a granite cliff 270 feet below the surface.

Widecker sank into the frigid lake on California's border with Nevada on July 10, 1994 after apparently suffering a medical or equipment problem. He had not been seen since.

Tahoe is the second-deepest lake in the United States, reaching depths of 1,645 feet.

"This group was doing just a routine planned dive and it was literally a needle in a haystack. This diver went in the water in 1994 and they just happened to find him," El Dorado County Sheriff's spokesman Sgt. Jim Byers told Reuters.

"He was wedged in a crevice in the rock or he'd have gone all way to bottom and we'd never (have) found him," Byers said.

The group, which could descend further than conventional recreational divers by using more sophisticated mixed-gas equipment, discovered Widecker still wearing a wetsuit and buckled into his scuba gear and air tank, Byers said.

"They immediately recognized that this was not a diver who should be down there," he said. "Very obviously he was deceased. They surfaced and contacted us."

Authorities were able to locate the ledge using a remote-controlled mini-submarine and recovered Widecker's body, which has undergone an autopsy to determine what caused his death nearly two decades ago.

"Here we have a diver in 270 feet of water that stays at 36 to 38 degrees constantly, doesn't change much," Byers said.

"Because he had wetsuit on he was protected from the elements and was just remarkably preserved. From a pathological standpoint it's pretty incredible," he said. "Literally, it's a little spooky."

Widecker was last seen in 1994 by a friend and dive partner, who reported seeing him sinking quickly in the lake, his respirator out of his mouth. The friend was unable to save him at the time.

Byers said that in 2001, a group of divers came across Widecker's body and tied a buoy line to it, but the line snapped and authorities were unable to find the spot.

Widecker's body still had the broken buoy line attached to it when it was recovered, Byers said.