Yesterday, nearly four months after police found the decomposing body of a newborn in a Drexel Hill car trunk, two different law-enforcement agencies disputed the status of the investigation.

Upper Darby Police Superintendent Michael J. Chitwood said that an autopsy report had been completed and that Delaware County Medical Examiner Frederic N. Hellman wouldn't disclose the conclusion to township detectives, which Chitwood called unprecedented and troubling.

Chitwood said he had never seen this in his 43-year career.

Hellman did not return a telephone call seeking comment.

Joseph J. Brielmann, a spokesman for the District Attorney's Office, said that the report was not finished and that Hellman was awaiting additional information. Brielmann said in a written statement that the report "will be forthcoming early next week."

Hellman's findings - expected to declare whether the 5- to 6-pound boy was alive at birth or stillborn - are necessary to determine whether charges will be filed against Mia Sardella, the 19-year-old Drexel University freshman who gave birth Jan. 1.

Police said potential charges range from desecration of a corpse to homicide.

Chitwood said he called yesterday's news conference after Upper Darby investigators were excluded by the District Attorney's Office from a Wednesday meeting on the case, which Chitwood described as a breach of protocol.

Sardella's attorney, Arthur T. Donato Jr., said he had not seen any report.

Police found the baby's body on Jan. 22 after receiving a phone call from Donato, who said the girl's mother, Stephanie Leone, found the corpse in a bloody tote bag in her car trunk.

Donato said he made the call after being contacted by Leone's father, Albert E. Piscopo, chief executive of the Glenmede Trust Co., which manages funds that benefit the Pew Charitable Trusts and has other investors. Donato said Piscopo suspected that the baby's mother was his granddaughter.

Chitwood said "clandestine meetings" by the District Attorney's Office concerned him because they raised questions about whether a well-connected family was receiving special treatment.

"They want us out of it," he said of the county prosecutors. "We're too open."

Brielmann said the case was being handled the same way that it would be for any other family.

Chitwood disagreed.

"I fault a system that does not share information in a case of this magnitude. . . . Four months is too long," he said. "Right now there is no justice for this baby."