Families of 9/11 victims have been told by the US Attorney General he is "deeply disturbed" that journalists may have hacked their phones.
Eric Holder confirmed there was sufficient reason to take the claims seriously, and he has launched an official investigation into allegations phone messages may have been intercepted by journalists from the News of the World (NOTW).
Relatives of seven 9/11 victims and two of their lawyers met Mr Holder, three officials from the FBI and five members of the Department of Justice. Members of two other victims' families took part via a video link.
During the 75-minute meeting, Mr Holder told them there was "sufficient predicate" to hold a preliminary criminal investigation. He stopped short, however, of saying what his investigators have found.
Norman Siegel, a lawyer at the meeting who represents 9/11 family organisations, said: "The Attorney General said the allegations were very disturbing and that it was a high priority for him. He confirmed there is what they called a preliminary investigation. He said this was the beginning of a dialogue with the 9/11 community. He said this was an initial meeting. I would hope we will hear from them within a few weeks – if not, I'll call them."
Separately, it has emerged that David Cameron sponsored a House of Commons pass for his communications chief, Andy Coulson, which the former NOTW editor obtained without disclosing ongoing payments and benefits worth hundreds of thousands of pounds from Rupert Murdoch's media empire. Mr Coulson may have broken parliamentary rules when he failed to declare his severance package on an official register when he obtained his first pass in September 2007. At the time, Mr Coulson was receiving health insurance, the use of a company car and the payment in instalments of two years' salary remaining on his contract from News International.
The revelation, reported by The Guardian, that Mr Cameron personally backed Mr Coulson's application for a pass increases pressure on the Prime Minister over his decision to employ the former tabloid editor. Tom Watson, the Labour MP, last night wrote to the parliamentary standards commissioner making a formal complaint against Mr Coulson and calling for an investigation.
A Conservative Party spokesman said: "It is the individual's responsibility to declare relevant financial interests to the parliamentary pass office."
The extent of the financial links between Mr Coulson and News International was brought into further question yesterday with allegations that his legal fees to date – likely to run into six figures – are being paid by Mr Murdoch's company. News International, which says it is "fully co-operating" with the police investigation into phone hacking, refused to confirm or deny it was paying Mr Coulson's legal fees or whether it was considering putting an end to any such arrangement.