The Maryland medical examiner's office ruled out shooting, stabbing, beating or strangulation yesterday in the deaths of an unidentified man and young woman whose decomposed bodies were found Monday night by Prince George's County police.

The preliminary autopsy was unable to identify the man, who appeared to be in his thirties, or the woman, who appeared to be in her late teens, county police said.

The bodies were found in a house near Camp Springs.

It was the second case of mysterious deaths in the county in the last three months. Three persons were found shot to death Feb. 28 in their home near Glenarden. In both incidents, the houses were equipped with expensive burglar alarms and showed no signs of forced entry or struggle, police said. The expensive furnishings also were left untouched in both houses.

A toxicology study of the victims found Monday will look for chemical causes of death, the medical examiner's office said. The study is to be completed in a few weeks.

Police found the bodies about 6 p.m. Monday at 5319 Old Branch Ave., in a neighborhood of split-level, $100,000 homes about one-half mile south of the Capital Beltway. The bodies had been in the home about 10 days, police said.

There was no sign of any property being taken or disturbed, said police spokesman Bruce Gentile.

Rod O'Neil, who lives next door to the home, said he called police after he noticed that the owner's Doberman pinscher appeared to be dead in the back of the house. "I became concerned when I didn't get an answer at the door," O'Neil said, "so I poked around and decided to call the police."

The house was purchased last November by Dennis C. White, according to county records, for more than $90,000. Police found four vehicles parked in the home's driveway -- a 1986 Nissan 300 ZX and a BMW, Mercedes-Benz and Chevrolet van, all 1985 models registered to White.

A police source said White, who is from Jamaica, was under surveillance by county vice officers in connection with an investigation of a drug ring with New York connections responsible for much of the distribution of cocaine and marijuana around upper Southern Avenue.

While police are not sure the man's body is White's, they said they are not looking for White until final autopsy results are in.

In the Feb. 28 slayings near Glenarden, Stephen E. Wade found the bodies of his brother, girlfriend and 7-year-old daughter in his home. Their hands had been bound with lamp cord; the two adults were shot in the head and the girl was shot in the buttocks.

Wade, of 3616 St. John's Place, is facing trial on charges of distributing and possession of PCP and cocaine and several weapons charges. No arrests have been made in the slayings.