The News of the World investigator at the heart of Britain's phone hacking scandal has been ordered by a court to reveal who instructed him to illegally access voicemails, lawyers said.
Glenn Mulcaire, who was jailed for six months in 2007 for intercepting messages on royal aides' phones, has until August 31 to provide the information, which could be damning for executives at the Rupert Murdoch-owned tabloid.
Media law firm Schillings won the disclosure order in February at the request of actor Steve Coogan, whose phone was among those hacked, but Mulcaire had sought to appeal. However, the Court of Appeal has now refused him permission, the lawyers said.
Mulcaire must disclose who instructed him to hack the phones of numerous personalities, including model Elle McPherson, celebrity PR guru Max Clifford, football agent Sky Andrew, Liberal Democrat deputy leader Simon Hughes, Gordon Taylor, former head of the Professional Footballers' Assocation, and PFA legal advisor Jo Armstrong.
Schillings lawyer John Kelly said it was a "very significant development, as Mulcaire will now have to identify exactly who at the News of the World asked him to access the mobile phones of the named individuals and who he provided the information to at the News of the World".
After Mulcaire and the News of the World's royal editor Clive Goodman were jailed in 2007, the newspaper's parent company, News International, insisted that the practice of hacking was confined to the two men.
But mounting evidence to the contrary prompted the police to reopen their investigations into hacking in January.