NEW YORK (Reuters)—The U.S. Federal Bureau of Investigation is examining allegations that Rupert Murdoch's News Corp may have tried to hack into the phone records of victims of the Sept. 11, 2001, attacks on the United States, the agency said on Thursday.

"We're looking into allegations raised by the letter by Peter King yesterday," said an FBI source, asking not to be identified.

Rep. King, R-N.Y., called for the investigation after Britain's The Daily Mirror newspaper on Monday first reported the possible hacking.

News Corp. declined to comment on the FBI probe.

The Daily Mirror reported that News of the World journalists offered to pay a New York police officer to retrieve the private phone records of victims of the Sept. 11 attacks. The Mirror, citing an unidentified source, said journalists wanted the phone numbers of the dead as well as details of the calls they made and received in the days leading to the attacks.

U.S. law enforcement and congressional officials told Reuters that they were unaware of any evidence or other information beyond the Daily Mirror story to support the 9/11 hacking claim. The Mirror was a tabloid rival to the now shuttered News of the World.

The officials told Reuters that the main reason an investigation had been requested and opened was that the Mirror claims were so serious and had attracted so much attention.

Legal experts said that even if there had been an attempt to obtain the records, it would be very difficult to uncover.

"It would be a very, very involved and elaborate investigation unless they have someone on the inside of the scheme who is providing information," said Roland Riopelle, a partner at Sercarz & Riopelle and a former federal prosecutor.

News Corp. chief Rupert Murdoch last week shut down the News of the World, Britain's top-selling Sunday tabloid, on a growing firestorm of allegations that its journalists had illegally accessed voicemails of thousands of people, from child murder victims to the families of Britain's war dead.