Contamination at a city laboratory may have led to the match between DNA found at the murder scene of a Juilliard student eight years ago and a chain used at a recent Occupy Wall Street protest, law-enforcement sources said Wednesday.

Two sources said officials are investigating whether at an NYPD lab technician came into contact with both pieces of evidence, causing the match.

Earlier in the day, Ellen Borakove, a spokeswoman for the medical examiner's office, said all employees there were screened as possible sources of the DNA. All of them were ruled out as the source of possible contamination, she said.

The DNA of the crime-scene detective who handled the chain has also been ruled out, sources said.

Further testing to try to finalize the source of the DNA is continuing.

"We are still actively investigating the DNA match," said Borakove. 

NBC 4 New York reported Tuesday that DNA evidence from the scene of Sarah Fox's murder in Inwood Hill Park in 2004 has been connected to DNA from a chain left at the Carroll Street F station in Brooklyn during a protest at 7:05 a.m. on March 28.

Fox was found nude and strangled in the park in May 2004, days after she disappeared during a daytime jog. Investigators recovered her pink CD player in the woods just yards from her body.

In March, protesters chained open emergency gates and taped up turnstiles in eight subway stations and posted fliers encouraging passengers to enter for free.

"I hope the person or persons who killed this young woman are found and brought to justice," said Bill Dobbs, a spokesman for Occupy Wall Street. "We don't know anything about it... I hope no one jumps to any conclusions."

Dimitry Sheinman, 47, has long been considered a suspect in the Fox murder because he publicly proclaimed to have information on the murder of Fox and her killer. He was never charged in the case and has been living in South Africa.

Sheinman recently returned to New York City, again proclaiming to have knowledge of the killer's identity. 

"I provided the police department with information I acquired by clairvoyant means by five separate people," he told NBC 4 New York Wednesday. 

Sources said Sheinman remains a leading person of interest. His DNA, which police have on file, was not found on the chain or at the 2004 murder scene. Sheinman said he was not in New York City on the day of the Occupy protest, and that he was in Capetown working on a book. 

"Just because police try to implicate somebody does not make them into a suspect," he said. 

Police Commissioner Ray Kelly said Wednesday he would not confirm, deny or comment on the DNA match. 

"Information has leaked out," he said. "The information has not come officially from the police department." 

No one was arrested in the March subway protest incidents. Asked Wednesday why police tested the chains for forensic evidence, Kelly said, "If we are able to identify someone who committed a crime using forensic evidence, we are going to use it."

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