Feds Probe Hacking As Scandal Hits USA
It is the first significant investigative step in the United States in a scandal which has engulfed the company in the UK.
Peter King, a Republican congressman from New York, had called on the FBI to launch an investigation into allegations of what he called "contemptible" behaviour.
An FBI official in New York told Sky News it is "looking into the allegations".
The Daily Mirror reported that News Of The World journalists offered to pay a former New York police officer to retrieve the private phone records of victims of the September 11 attacks.
It was claimed they 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.
Law enforcement officials in the US say they are unaware of any other evidence to support the claim but that the allegation was serious enough to merit an investigation.
Congressman King said:
"The thought that anyone would have hacked into the phones of those who were killed or missing or their family members at that tragic time is contemptible. That is why I have asked the FBI to do an investigation and report back on it."