NEW YORK - The FBI has opened an investigation into allegations that media mogul Rupert Murdoch's News Corp. sought to hack into the phones of Sept. 11 victims, a law enforcement official said Thursday.

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

The official stressed that the probe was in its infancy but declined to discuss the scope of it or say whether any investigative steps had been taken.

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

A rival newspaper reported last week that the News of the World had hacked into the phone of U.K. 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.

U.S. 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 U.S. attorney's office in New York declined comment. There was no immediate response to a phone message left for News Corp.

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.

On Thursday, Murdoch caved in to pressure from Britain's Parliament as he and his son James first refused, then agreed, to appear next week before lawmakers investigating phone hacking and bribery by employees of their newspaper empire.

Murdoch began his media career in Australia in 1952 after inheriting The News newspaper after the death of his father, and he has built News Corp. into one of the world's biggest media groups. Assets include Fox News, the 20th Century Fox movie studio, The Wall Street Journal, the New York Post and three newspapers in Britain -- down from four with the death of the News of the World.

Also on Thursday, Scotland Yard said it had made its seventh arrest related to the inquiry into phone hacking at the now-defunct tabloid, whose closure was a doomed effort to keep alive a bid for the highly profitable network British Sky Broadcasting. Police didn't disclose the name of the arrested man.