Glenn Mulcaire may have to hand over details of his contacts

Glenn Mulcaire, the private investigator at the centre of the News of the World phone-hacking scandal, could be forced to hand over details of his journalist contacts at a succession of cases due to come to court.

Earlier this year, Mulcaire was the subject of a disclosure order issued by Mr Justice Vos to the publicist Max Clifford, who took out a private action against Mulcaire as well as against News Group Newspapers, publishers of the News of the World, after alleging that his phone had been hacked. The case was settled out of court before the disclosure order was enforced, with Mr Clifford believed to have received a settlement of £1m.

Mulcaire is being sued by the football agent Sky Andrew and has not issued a defence against the claim, which may cause difficulties for News Group, which is also being sued. When Mulcaire was jailed for six months in 2007 he admitted hacking into Mr Andrew's voicemail as well as that of four other high-profile individuals.

In a separate case, where Mulcaire is being sued by the former MP George Galloway, the former private investigator is defending the claim and has hired a firm of London solicitors, Russell, Jones & Walker. Mulcaire has also hired the media barristers 5 Raymond Buildings. His denial of these charges does not prevent the court from ordering Mulcaire to make full disclosure of his contacts.