Was David Cameron a hacking target?

David Cameron could have been among the phone-hacking targets at the News of the World, it emerged last night.

With the list of potential victims seemingly growing by the hour, No 10 refused to deny claims that Mr Cameron fears he is among them.

Last Wednesday it emerged that the Chancellor, George Osborne, was told by police that his name and home phone number appeared in notes kept by Glenn Mulcaire, a private investigator, and Clive Goodman, the former NOTW royal reporter, who were both jailed for phone-hacking over a story about Prince William in 2005.

A spokesman for Mr Osborne said: "They had no further evidence to suggest George's voicemail had been hacked or attempted to be hacked. George was very grateful to the police. Frankly he thinks there are far more serious allegations surrounding the whole hacking affair."

However, in the summer of 2005 – when hacking is thought to have been most widespread – Mr Osborne was running Mr Cameron's Tory leadership bid. At the time Mr Cameron faced questions about his student days and unsubstantiated claims of drug-taking. Last night an aide to Mr Cameron said he had not been contacted by police investigating the hacking allegations. But senior Tory sources believe it to be highly likely that his campaign to lead the opposition was targeted by one newspaper or another.

Deputy Assistant Commissioner Sue Akers, who is leading the hacking investigation, has revealed that there could be as many as 4,000 potential victims – far more than previously thought. "I understand that many people may be upset and will want to seek information from us," she said on Thursday. "I ask them to be patient and reassure them we will contact them if they are affected, but it will take time."