Those comments are fueling arguments by Assange's lawyers, who contend that if Assange was extradited to Sweden, the country could bow to U.S. pressure. The U.S. Attorney General's office has been investigating Assange, but no charges have been filed.

"It is submitted that there is a real risk that, if extradited to Sweden, the U.S. will seek his extradition and/or illegal rendition to the USA, where there will be a real risk of him being detained at Guantanamo Bay or elsewhere," according to the document.

The Guantanamo Bay detention center, in Cuba, was established in 2002 by the administration of President George W. Bush to hold military combatants from the wars in Afghanistan and Iraq outside of U.S. legal jurisdiction. It was meant to hold people who were to be tried in military courts. A case brought by the U.S. Department of Justice would be heard in a civilian court. U.S. President Barack Obama pledged to close Guantanamo when he took office in January 2009, but political controversy has hampered the effort.

Assange's defense, however, appears similar to that of , the British hacker who is awaiting a decision from the Home Office on whether he should be extradited to the U.S. on computer hacking charges. At one point during his appeal, McKinnon's attorneys argued he could be classified as a terrorist since the U.S. accuses him of disrupting military networks after the Sept. 11, 2001, terrorist attacks.

Assange's lawyers also plan to make several technical legal arguments about how Sweden has pursued Assange. They will argue that Swedish prosecutor Marianne Ny was not authorized to issue a European Arrest Warrant, and that extradition merely for the purpose of questioning a suspect is not in line with British law.