A United States court has ordered Twitter to hand over details of the accounts of WikiLeaks and several supporters as part of a criminal investigation into the release of hundreds of thousands of confidential documents.

The December 14 subpoena obtained by the US Department of Justice and published by online magazine Salon.com on Friday said the records sought from the microblogging website were "relevant to an ongoing criminal investigation."

It ordered Twitter to provide account information on WikiLeaks founder Julian Assange and Bradley Manning, the US Army intelligence analyst suspected of leaking Pentagon documents made public last year by WikiLeaks.

The information sought by the US government includes all connection records and session times, IP addresses used to access Twitter, email and residential addresses plus billing records and details of bank accounts and credit cards.

The subpoena included the accounts of WikiLeaks supporters Jacob Appelbaum, Rop Gonggrijp and Birgitta Jonsdottir, a former WikiLeaks volunteer and member of Iceland's parliament.

"WikiLeaks strongly condemns this harassment of individuals by the US government," Assange's lawyer, Mark Stephens, said in a statement issued in London.

The US government is examining whether criminal charges can be brought against Australian-born Assange for helping to make public hundreds of thousands of confidential US diplomatic cables that embarrassed Washington and several of its allies.

Mr Stephens said three of the four individuals targetted by the Department of Justice had never worked for WikiLeaks and were private citizens who supported WikiLeaks voluntarily as activists or politicians.

Two of them were instrumental in helping WikiLeaks make public the Pentagon video that showed a US helicopter crew firing on Iraqi civilians, Mr Stephens said.

WikiLeaks is instructing its US lawyers to oppose the subpoena, he added.

Ms Jonsdottir said she was seeking legal advice and had spoken to Iceland's minister of justice, who is looking into the case.

"I have nothing to hide and have done nothing wrong - I have no intention to hand my information over willingly to DoJ (Department of Justice)," Ms Jonsdottir wrote on Twitter.

The subpoena gave Twitter Inc three days to provide the records and ordered the San Francisco-based company not to inform the users under investigation.

A federal judge unsealed the order on January 5 after Twitter requested the right to inform the people involved.

Mr Stephens said this legal action by Twitter had made public the existence of a criminal investigation of WikiLeaks.

The lawyer called on Facebook and Google to unseal any similar subpoenas requesting information about WikiLeaks.

Washington has accused WikiLeaks of acting without regard for the safety of those named in the cables, which contained candid remarks and assessments of foreign leaders and governments.

On Friday, the US State Department said it had warned several hundred people worldwide it believes may be imperilled by the release and has helped a handful of them relocate to safer places.

- Reuters