NEW YORK - The FBI has begun a preliminary inquiry based on concerns in Congress over a report that media mogul Rupert Murdoch's News Corp. sought to hack into the phones of September 11, 2001 terror attack victims, a law enforcement official said Thursday.

The decision to step in was made after US Rep. Peter King and several other members of Congress wrote to FBI Director Robert Mueller demanding an investigation, said the official, who spoke to The Associated Press on condition of anonymity because the official wasn't authorized to speak publicly.

The official stressed that the review was in its infancy but declined to discuss the scope of it or say what steps had been taken. The FBI routinely makes preliminary inquiries into issues raised by lawmakers and others to determine whether a full-blown investigation is needed.

News Corp., based in New York, has been in crisis mode because of a scandal that sank its British newspaper the News of the World.

A rival newspaper reported last week that the News of the World had hacked into the phone of UK teenage murder victim Milly Dowler in 2002 and may have impeded a police investigation into her disappearance. More possible victims soon emerged: other child murder victims, 2005 London bombing victims, the families of dead soldiers and former Prime Minister Gordon Brown.

The suggestion that September 11, 2001 victims also may have been were targeted surfaced Monday in the Mirror, a British competitor of News Corp.'s The Sun. The newspaper quoted an anonymous source as saying an unidentified American investigator had rejected approaches from unidentified journalists who showed a particular interest in British victims.

British Prime Minister David Cameron vowed Wednesday that the claim would be investigated there.

US Department of Justice spokeswoman Laura Sweeney said Thursday that the department "does not comment specifically on investigations, though anytime we see evidence of wrongdoing, we take appropriate action."

The FBI and the US attorney's office in New York declined to comment.

King's letter had called for "an immediate investigation," saying it was an "urgent matter."

King, a Republican, said Thursday afternoon he had not officially been contacted by the FBI and said he wanted to reserve comment until he hears from the agency.

"If they do, I'd be gratified," he said in a brief telephone interview with the AP.