he body of accused presidential assassin Lee Harvey Oswald was exhumed from a Fort Worth cemetery early today, and after a four-hour autopsy, a team of doctors declared that "beyond any doubt" it was Oswald who had been buried in the grave 18 years ago.

The exhumation and autopsy of the man who allegedly killed President John F. Kennedy on Nov. 22, 1963, ended three years of legal maneuvering and put to rest the theory of a British author, Michael Eddowes, that Kennedy had been killed by a Russian agent posing as Oswald and that it was the agent who had been buried as Oswald.

"Beyond any doubt--and I mean absolutely any doubt--the person buried under the name Lee Harvey Oswald is in fact Lee Harvey Oswald," said Dr. Linda Norton, an associate professor of pathology at the University of Alabama, who headed the team that examined the remains.

The team, which included two forensic pathologists and two forensic odontologists, based their findings on a comparison of Oswald's Marine dental records made before he defected to Russia and a set of 16 dental X-rays made today.

Doctors also matched a defect on the left mastoid bone with records of surgery done on Oswald as a young boy. In addition, two rings on the little finger of Oswald's left hand were identified by his widow, Marina Oswald Porter, as those placed there just before his burial in November, 1963. Oswald was shot to death by nightclub owner Jack Ruby two days after Kennedy was assassinated.

Jerry Pittman, a lawyer representing Mrs. Porter, who had agreed to the exhumation more than a year ago, said she was "totally satisfied" by the results of the autopsy.

Eddowes, who financed the operation, said in a statement read by one of his lawyers, "Though surprised, I am in no way disappointed in the apparent disproving of my evidence of imposture. Rather I have accomplished my objective in obtaining the exhumation and I am glad for those who have steadfastly maintained the contrary for whatever reason."

The exhumation, which began in darkness early today, was made possible when Oswald's older brother, Robert, decided to drop his legal fight to prevent the removal of the body. A temporary restraining order blocking the exhumation had expired at midnight Saturday.

Security guards arrived about 4 a.m. CDT today at the gravesite at Rose Hill Burial Park in Fort Worth. About 6:45 a.m., a backhoe began to scoop out the earth above Oswald's grave. A tent had been placed over the gravesite "for dignity," according to cemetery manager Neil Wretberg. Nonetheless, news helicopters hovered over the cemetery. Reporters and photographers, who had been alerted to the exhumation late Saturday, were able to get no closer than 30 yards from the site.

The digging stopped a few inches above the concrete vault surrounding the casket, according to William C. Dear, a private security agent who was in charge of security.

Dear said the vault was cracked and the oak casket had deteriorated so badly that a makeshift pasteboard box was needed to lift the casket and body out of the grave.

The body was badly decomposed, according to the doctors. Oswald's skeleton was covered with "a cheesy, white type of tissue," Norton said at a press conference. Others who saw the body said there was some hair remaining on the scalp and that Oswald's clothes were still there.

With the help of large belts, the casket was hoisted out of the ground and placed in a black hearse. Mrs. Porter remained in a car at the site during the exhumation. Her husband, Kenneth, a carpenter in the nearby town of Rockwall, observed the removal of the casket.

About 9:15 a.m., the motorcade left the cemetery for the 45-minute drive to Baylor University Hospital in Dallas.

The autopsy began about 10:30 a.m., with about 15 people present. A court reporter made a record of the autopsy and the entire operation was videotaped at the request of Mrs. Porter.

Norton said there was no evidence that the casket had been tampered with during the 18 years it had been in the ground. She said Oswald's body was in the same state of repose as at burial and that a "mist of mold" covering the body indicated the remains had not been touched.

Because of the deterioration of Oswald's body, doctors severed the skull from the neck and removed the skull for the dental examination. According to Dr. Irvin Sopher, West Virginia state medical examiner and professor of pathology at the West Virginia University medical school, Oswald's teeth were first cleaned, then X-rayed and charted. The teeth and new X-rays were compared with earlier written records and X-rays retrieved from medical archives of the armed services. These records dated from 1956-59.

"Fortunately, we had good dental records," Sopher said.

Saying that the matching of dental records can be "as exact as a fingerprint," Sopher said there "is no doubt that the in-life records and the X-rays match the body in the casket."

Mrs. Porter identified the two rings, one yellow metal, the other white with a red stone.

The team of doctors also measured Oswald's body and "guesstimated" his height at 5 feet 9 inches.

The autopsy concluded about 2:20 p.m. Oswald's remains were put into a body bag and then into a new metal casket for planned reburial in the original gravesite.

The exhumation and autopsy cost an estimated $10,000-$12,000 and was financed entirely by Eddowes, according to his lawyer, John Collins.

Norton said an immediate report on the autopsy will be made but will remain the property of the doctors and the family. She said the Porters had given the team permission to publish in a scientific journal a detailed description of the findings of today's autopsy. That will not be done for months, she said.

Oswald's older brother, Robert, who has spent an estimated $13,000 on the legal fight to prevent exhumation, decided to drop it "for family reasons" early last week, according to his attorney, Craig Fowler. That set into motion the secret negotiations that led to today's events.

Norton said she first had been contacted a year ago by Mrs. Porter and began putting a team together a few months ago. In addition to Sopher, the team included Dr. James A. Cottone of the University of Texas Health Science Center at San Antonio, and Dr. Vincent DiMaio, medical examiner for Bexar County (San Antonio).

Norton said she was alerted on Friday that the exhumation would take place today. Similarly, Baylor University Hospital was contacted on Friday about the autopsy.

Oswald's widow, who had said she expected to find no body in the grave, hoped the autopsy would disprove Eddowes' theory, her attorney said.

Mrs. Porter told United Press International today, "I always intended for this to be a private matter, but it became public because of circumstances beyond my control. It's very unfortunate it became such a public event. Now I have my answers, and from now on, I only want to be Mrs. Porter."