THE FBI is to investigate allegations Rupert Murdoch's News Corp tried to hack into the phone records of victims of the 9/11 terror attacks, it emerged last night.

The latest dramatic twist to the phone hacking scandal could potentially deliver a serious blow to the media mogul’s global business empire.

The FBI said it was examining allegations raised in a letter to the criminal investigation agency about reports a News of the World journalist offered to pay a New York police officer to retrieve the private phone records of victims of the terrorist attacks on the Twin Towers on September 11, 2001.

A source said: “We are looking into allegations raised by the letter by Peter King yesterday.”

The influential New York congressman, chairman of the House of Representatives’ Homeland Security Committee, wrote to FBI director Robert Mueller demanding the move after the UK allegations first surfaced.

An official also confirmed the FBI had now received letters from other members of the US Congress.

“The 9/11 families have suffered egregiously, but unfortunately they remain vulnerable against such unjustifiable parasitic strains. We can spare no effort or expense in continuing our support for them,” Mr King told Mr Mueller in his letter.

Calls for an investigation have also been made to the US Justice Department and the country’s Securities and Exchange Commission (SEC).

Democratic senators Barbara Boxer, Jay Rockefeller and Frank Lautenberg asked attorney general Eric Holder and SEC chairman Mary Schapiro to look into potential violations of the Foreign Corrupt Practices Act.

“The reported allegations against News Corporation are very serious and indicate potentially thousands of victims and a pattern of illegal activity. It is important to ensure no United States laws were broken and no United States citizens were victimised,” Mr Rockefeller and Ms Boxer wrote in a letter to Mr Holder and Ms Schapiro.

Mr Lautenberg pointed out that, as a US-based company, News Corp and its employees were subject to the anti-bribery provisions of the Act. If bribes were made and not properly recorded in the company’s books this would also be a violation, he added.

“The limited information already reported in this case raises serious questions about the legality of the conduct of News Corporation and its subsidiaries under the FCPA,” Mr Lautenberg said in a separate letter to the Justice Department and the SEC.

The police officer – now a private investigator – said he turned down the request because of “how bad it would look”.

A Justice Department spokeswoman said the letters would be reviewed as part of standard practice but that did not mean an investigation would be initiated.

Mr Murdoch rejected criticism of his company’s handling of the crisis in his first major interview on the issue last night.

He told The Wall Street Journal, one of News Corp’s US titles, that an independent committee would “investigate every charge of improper conduct”. He said News Corp and News International, which closed the tainted News of the World, had responded “extremely well in every way possible”, making just “minor mistakes”.

And, despite News Corp’s withdrawal on Wednesday of its £8bn bid for BskyB and the damage to its reputation, Mr Murdoch, 80, said there was “nothing that will not be recovered. We have a reputation of great good works in this country”. He admitted to being “annoyed” over the scandal, but added: “I’ll get over it.”

The media tycoon said he had acted appropriately and swiftly. He also backed his son James, chairman of News International. Mr Murdoch added: “I think he acted as fast as he could, the moment he could.”

Mr Murdoch’s assets in the US include Fox News, 20th Century Fox movie studio and the New York Daily Post.

News Corp declined to comment on the FBI probe.