The US state department has told the BBC it believes an alleged whistle-blower obtained secret diplomatic data despite being at a field base in Iraq.
Serviceman Bradley Manning, 22, faces two charges related to the illegal transfer and transmission of classified information from a US military network.
The US said he was suspected of downloading from SIPR Net.
He reportedly then passed on the data, including army videos and diplomatic messages, to the WikiLeaks website.
WikiLeaks has repeatedly said it does not have the confidential messages and the site itself is not mentioned in the charges against Private First Class (Pfc) Manning.