A private detective jailed for illegally intercepting voicemail messages on behalf of a journalist at one of Rupert Murdoch's British tabloids on Friday gave lawyers the names of the people he says ordered him to carry out the phone hacking.
Glenn Mulcaire's lawyer, Sarah Webb, said no details would be released before legal moves by her next week to prevent their publication while a police probe continues into allegations of phone hacking by the now closed News of the World newspaper.
Disclosure of the names would add pressure on News International, the British newspaper arm of Murdoch's News Corp and shed further light on how widespread phone hacking was at the tabloid.
Mulcaire, jailed in 2007 along with paper's royal reporter Clive Goodman, had been ordered to hand over the details by a court judge.
Webb said the document containing the names had been delivered late on Friday to lawyers representing actor Steve Coogan, who had sought the disclosure from Mulcaire.
She would not say how many names were contained in the document. News International had maintained until recently that phone hacking was limited to a single rogue reporter.
Coogan, represented by lawyers Schillings, believes his phone voicemail messages were hacked and is suing News International.
Webb said the document would formally be lodged at London's High Court on Tuesday, following a public holiday on Monday.
She said Schillings had agreed not to disclose the names before legal attempts to block publication.
In conjunction with the Metropolitan Police we at the moment believe that the names, in the interest of the administration of justice, should not be released at present. The matter will be clarified next week, Webb told Reuters.
She said there was a danger that publication could prejudice any criminal prosecutions launched as a result of the investigation by London's police service.
Goodman and Mulcaire were convicted in 2007 for illegally accessing the voicemails of royal aides and five other figures including the model Ellie Macpherson.
Following civil action from a number of individuals who believed their phones had been hacked, News International admitted earlier this year it had evidence the practice was more widespread, prompting the police inquiry.
Some executives, including Murdoch's son James, chairman of News International, face accusations they knew about the illegal activities at a far earlier date than they had previously admitted.
Other senior figures, including former editorial staff on the News of the World, have been arrested by police probing the allegations the tabloid's journalists illegally intercepted the voicemails on mobile phones of celebrities, politicians, as well as victims of crime and their families.
It has also caused embarrassment for Prime Minister David Cameron whose former media chief Andy Coulson, a former News of the World editor, is one of those arrested as part of the probe.
News International closed the News of the World in July following the disclosure that the phone of a missing schoolgirl, later found murdered, had also been hacked.