Human limbs found in a cave near Dubois last week probably came from the same unidentified body as a torso found in 1979, Clark County authorities say.

Sheriff Craig King said Monday that he wants to solve the 11-year-old mystery, which investigators consider a case of homicide. But he said it will be difficult unless someone finds the victim's skull.The Idaho Bureau of Investigations and the FBI have been called in, and the limbs will be sent to an FBI laboratory. King plans to organize a search of the cave for more evidence.

"I'd like to get that skull," he said. "That's where the cause of death would show."

Lynn Thomas of Dubois said he and his daughter, Lynette Rogers of Renton, Wash., and her children, Nathan, 15, and Anna, 11, found an arm Friday morning while exploring caves once used for fallout shelters about one mile north of Dubois.

People looking for artifacts found an unidentified man's torso in the same cave on Aug. 26, 1979. The circumstances of the man's death have never been determined, but authorities are still treating it as a homicide.

Thomas said family members had been talking about the torso found almost 12 years before when they came across the additional remains Friday.

"My daughter shined a flashlight on it, and it was a human hand," Thomas said.

He said the hand was still attached to an arm with a piece of a sweater on it, close to a hole in the ground. The family left the cave and notified King's office.

The sheriff said authorities discovered another arm next to the one Thomas' family found. Bits of burlap sack were still attached to both arms. In the hole, authorities also found two legs wrapped in a deteriorated burlap sack.

King believes the limbs belong to the same body as the torso, which was found about 100 feet deeper into the cave. Clothes on the limbs appeared to match those found on the torso, including dark wool pants, a white cotton shirt with pink stripes and a maroon sweater.

The torso also was found wrapped in burlap.

The limbs were cleanly severed from the body, possibly with a saw, King said, although there were no wounds on the torso. He said a medical examiner's report concluded that the man died six months to five years before the remains were found.

The arms and legs still have shriveled, leathery flesh on them, King said and were well-preserved in the cool, dry cave.

"Somebody killed him, that's for sure," Earl Holden, who was Clark County sheriff at the time the torso was found, said Tuesday.

But neither Holden nor King have any solid ideas about what happened to the man.

King said all he knows about the man is that he was a Caucasian. Having the legs and arms should help determine height and weight, but no positive identification is possible without a skull.

The remains found Friday probably were uncovered within the past six months, the sheriff said, because he and others had been in the cave within the last year and had noticed nothing.

He said the hole that contained the remains appeared to have been dug with a shovel, not by an animal.