WikiLeaks has called upon Google and Facebook to reveal the contents of any US subpoenas they may have received.
The demand came following news that a US court had ordered Twitter to provide details of accounts on the micro-blogging site of five people associated with the group, including Julian Assange.
According to the Guardian, as strong evidence of a US grand jury piecing the details of the communication links between US serviceman Bradley Manning and WikiLeaks emerged, some of those named in the subpoena said they would contest the disclosure. Manning is accused of stealing hundreds of thousands of sensitive government cables.
"Today, the existence of a secret US government grand jury espionage investigation into WikiLeaks was confirmed for the first time as a subpoena was brought into the public domain," WikiLeaks said in a statement.
In the writ, which has been approved by a Virginia court, the San Franscisco-based micro-blogging site has been asked to hand over all details of five individuals' accounts and private messaging on Twitter, including the computers and networks used.
Those named include WikiLeaks founder Julian Assange, Manning, Icelandic MP Brigitta Jonsdottir and Dutch hacker Rop Gonggrijp. Gonggrijp, Assange and Jonsdottir have been named as "producers" of the first significant leak from the US cables cache that included a video of an Apache helicopter attack that led to the killings of civilians and journalists in Baghdad.