LONDON (Reuters) - WikiLeaks founder Julian Assange will argue he should not be extradited from Britain to Sweden over alleged sex crimes because he could end up in the United States facing the death penalty, his lawyers said on Tuesday.

The 39-year-old Australian computer expert, who has infuriated Washington by releasing details of secret U.S. diplomatic cables on his website, is wanted for questioning by Sweden over allegations of sexual offences made by two WikiLeaks volunteers.

Following his brief appearance in a London court on Tuesday, lawyers published an outline of the defense he will use at a full extradition hearing next month, in which they said Assange faced possible execution in the United States.

“There is a real risk that, if extradited to Sweden, the U.S. will seek his extradition and/or illegal rendition to the USA,” said the document on the website of law firm Finers Stephens Innocent.

“Indeed, if Mr Assange were rendered to the USA, without assurances that the death penalty would not be carried out, there is a real risk that he could be made subject to the death penalty.”

If Assange ends up in the United States, the document adds, there is “a real risk” he would be subject to ill-treament or even torture, both prohibited under Article 3 of the European Convention on Human Rights.

Assange, who has protested his innocence over the sex offence allegations, sat behind a glass screen at London’s top security Belmarsh Magistrates’ Court during a hearing lasting less than half an hour.

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Afterwards, Assange said his organization would press ahead with its release of documents despite his own legal battle. WikiLeaks said in December it planned to release documents that would point to “unethical practices” at a major U.S. bank, widely thought to be Bank of America.

WORK “CONTINUES UNABATED”

“Our work with WikiLeaks continues unabated and we are stepping up our publishing for matters related to Cablegate and other materials,” Assange told reporters outside the court.

“Those will shortly be appearing through our newspaper partners around the world -- big and small newspapers and some human rights organizations,” he added.

A U.S. court has ordered microblogging site Twitter to hand over details of the accounts of WikiLeaks and several supporters as part of a criminal investigation into the so-called Cablegate release of hundreds of thousands of confidential diplomatic documents.

British police arrested Assange last month on a European warrant issued by Sweden. After spending nine days in jail, he was released on bail on December 16 after his supporters raised a surety of 200,000 pounds ($312,000).

The full extradition hearing will begin on February 7 and last two days. Even if he loses, Assange can appeal and the legal arguments could stretch on for months.

As part of his bail conditions, Assange was ordered to stay at a mansion in eastern England, abide by a curfew, report to police daily and wear an electronic tag.

However, the conditions were relaxed on Tuesday to allow him to stay at a journalists’ club in central London on February 6 and 7 to allow him to get to court on time.