Lawyers of a Briton accused of hacking U.S. military and NASA computers in 2001 are citing their client's autism as a reason why he should not be extradited to the U.S. for trial.

The British high court is to hear the new legal defense for Gary McKinnon, 40, on Tuesday as his lawyers warned he risks suffering from depression and may harm himself when he is transferred to U.S. custody because of his Asperger's syndrome. The condition was diagnosed in August.

McKinnon's attorney, Karen Todner, told Espiner she was hoping the High Court judicial review would prevent his extradition and secure a trial for him in the U.K., according to Cbsnews.com.

McKinnon has admitted to British authorities that he hacked 97 U.S. government computers from 2001 to 2002 in a search for classified documents about extra-terrestrial life. He was finally caught when he tried to download an image of a spacecraft from a NASA computer at the Johnson Space Center in Houston, TX.

In March 2002, McKinnon was arrested after he was identified as the hacker through his personal e-mail address. The U.S. Department of Homeland Security sought his extradition in October.