The latest sets of human remains found near a remote New York Beach are too old to be tied to the killings of four online escorts and may be the victims of another notorious Long Island serial killer, the New York Post reports.

Police hunting for a serial killer who strangled four prostitutes announced Tuesday that more human remains had been found this week near Jones Beach on Long Island.

But the latest remains predate the bodies of the four escorts found in December -- all in their 20s and found wrapped in burlap bags along a stretch of deserted ocean parkway, according to the newspaper.

An unnamed source told the New York Post that the remains -- reportedly a torso and human skull -- could be victims of convicted serial killer Joel Rifkin, who confessed in 1993 to killing 17 prostitutes and is serving a life sentence in upstate New York. Rifkin was convicted in nine of the deaths, but three of his victims were never found.

"These are so old that roots were growing around the vertebrae and the skull," the source told the newspaper. "These could be one or two of Joel Rifkin's victims who were never found."

A total of 10 sets of human remains have been found so far. The four bodies discovered in December were identified as prostitutes who advertised on Craigslist. Police in Suffolk County found four more sets of human remains in the last two weeks -- one reportedly believed to be a child -- but those bodies have not yet been identified.

Suffolk County Police Chief Richard Dormer said Wednesday he will not speculate on the "age, gender or condition" of the latest victims found.

Dormer said police divers are searching the waters just off the Cedar Beach marina for "any evidence" connected to the remains found. He also said the FBI will be using high resolution aerial technology to "help identify skeletal remains that might still be out there."

No suspect or person of interest has so far been named, and Dormer said Wednesday that investigators are "interviewing a lot of people."

"I'm not going to get into names for obvious reasons," he said.

Dormer also said the sets of remains found on Long Island are likely not connected to the 2006 deaths of four Atlantic City prostitutes. "The indications we have right now is that there is no connection," he said. 

The disappearance of 24-year-old New Jersey resident and Craigslist escort Shannan Gilbert led investigators to the Suffolk County beach spot late last year. None of the found victims, however, is Gilbert, whose case remains open.

WABC-TV reports that Oak Beach resident Dr. Charles P. Hackett was one of the last people to see Gilbert alive. Gilbert's mother told the station that she received a phone call from Hackett the day after she disappeared.

"He called me on the phone. He said he had a halfway house and that Shannan was there," Gilbert reportedly told the station. "She wanted to be off the streets and he was trying to help her."

Hackett, the former head of Suffolk County Emergency Medical Services and a former police surgeon, reportedly denies ever calling Gilbert's mother.

When asked about Hackett by a reporter on Wednesday, Dormer said "he's been very cooperative," though he did not mention the doctor by name.

Dormer also said police have received more than 600 tips in the case.

Police sources have said evidence suggests that whomever dumped the four bodies discovered in December is knowledgeable of police investigative tactics and familiar with the area of Long Island where the bodies were found, according to multiple press reports.

The person believed to be the killer made taunting phone calls to the teen sister of victim Melissa Barthelemy shortly after she disappeared in July 2009. The calls were difficult for police to investigate because they were all under three minutes and made from crowded places, like Madison Square Garden and Times Square.

Dormer said Wednesday that he believes the four murdered women found in December were targeted because they were sex workers, and he cautioned other prostitutes to "be very careful who they meet and where they meet them."

In an attempt to calm local residents' fears, Dormer said, "We don’t have someone running around Suffolk county with blood dripping from a knife."'s Cristina Corbin and The Associated Press contributed to this report