US attorney general Eric Holder has promised relatives of victims of the 9/11 terror attacks he will begin a preliminary criminal investigation into reports that News Corporation journalists tried to gain access to the phone records of the dead.

Family members who lost loved ones on 11 September 2001 met Holder at the Justice Department on Wednesday to discuss allegations first reported by the Daily Mirror that News of the World reporters attempted to gain unauthorised access to 9/11 victims' voicemails.

Norman Siegel, a lawyer representing some of the families, told reporters that the attorney general had said it was "very disturbing" that phones of 9/11 victims and their family members might have been hacked. The relatives met Holder for over an hour to discuss the allegations.

The hacking allegation was made in an article in the Mirror last month. The paper said NoW journalists had approached a former New York police officer working as a private detective and asked him to do the hacking, which he declined to do.

So far, no evidence has emerged to corroborate the story, which has been strenuously denied by News Corp. If the Justice Department finds any truth in the claims, News Corp would face a damaging battle with the US authorities as well as a rash of civil law suits from family members.

The US authorities have considered investigating News Corp, a company listed on the US stock markets, under the Foreign Corrupt Practices Act over payments allegedly made to police . But the 9/11 allegations are the most serious issue the firm has faced in the US over the scandal.

The Mirror story was based on unnamed sources, including one described as a former New York police officer who became a private investigator. Heclaimed to have rejected requests by journalists from the now closed NoW to retrieve private phone records of victims.

News Corp has dismissed the report as "anonymous speculation" with "no substantiation" and said earlier this month that the company was fully co-operating with all investigations into the firm.

Ahead of the meeting Siegel told Associated Press the families were working with the FBI to determine if hacking "was attempted, and/or occurred".

"We are going to the meeting with the attorney general to listen to what he can tell us about the investigation and to ascertain the scope, the goals and timetable of the inquiry," Siegel said.

Rupert Murdoch was asked about the 9/11 hacking claims when he was questioned by parliament last month. He said: "we have seen no evidence at all and as far as we know the FBI haven't either". He said he did not know if NoW employees or the private investigator Glenn Mulcaire took it upon themselves to do it.