It may take three weeks or longer to recover all of the bodies believed buried in a crawl space under the home of suspected mass murderer John Wayne Gacy, the Cook Country medical medical examiner said today.

The search has been turned over to archeologist, who are using the same painstaking techniques used to explore ancient ruins. "The crawl space has to be excavated properly to preserve the chain of evidence and help provide proper identification of the victims," said Dr. Robert J. Stein, the country medical examiner. "It's camelhair-brush work for sure."

Since the discovery of the mass grave site Friday in the unincorporated area of Norwood Park, just north of Chicago, the remains of nine bodies have been recovered. None of the bodies found in the crawl space has been identified.

Grace, 36, a remodeling contractor who once served a priso term in lowa for sodomy, reportedly told investigators that he raped and strangled 32 teen-age boys and young men. Investigators expect to find many of the bodies in the crawl space and buried nearby. Area rivers also are being dragged for six other youths Gacy reportedly said he killed.

Stein said every bit of dirt in the crawl space is being sifted by a trained crew under sifted by a Dr. Charles P. Warren, a University of Illinois forensic anthropoligist.

Every piece of evidence-strands of hair, teeth, pieces of clothing and bloodstains-is being catalogued so that its exact position will be known later.

Teeth of the victims are being examined by Dr. Edward J. pavlik, a forensic odontologist and regular consultant to the medical examiner's office.

Without dental charts on some victims, Stein said, identification may be impossible, although such clues as height, age, race and approximate time of death can be deduced in other ways.

Grace so far has been charged with one murder, that of robert Piest, 15, whose body Gacy reportedlu said he dumped into a river on Dec. 11. Piest's body has not been recovered.

Cook County sheriff's investigators said today that the body of a 15-year-old youth discovered last month in the Des Plaines River appears to be a victim of Gacy.

The youth, identified as Frank Landingin of Chicago, was found with underwear stuffed into his mouth.

He apparently died of strangulation, not drowning. Several of the other victims also had clothing stuffed into their mouths.

Authorise said they have the names of seven other alleged Gacy victims.Some of those were said to have been given to them by Gacy, and others, he is said to have identified from police photo files.