LONDON, UK: A Briton wanted in the United States for breaking into NASA and Pentagon networks in "the biggest military hack of all time" lost an appeal against his extradition on Friday, making a U.S. trial more likely.

Gary McKinnon, 43, has fought a three-year battle to avoid extradition, including going to the European Court of Human Rights, but he appeared to have run out of options as Britain's High Court ruled against his latest appeal on Friday.

The court rejected arguments by McKinnon's lawyers that extraditing McKinnon, who was recently diagnosed with Asperger's Syndrome, a form of autism, would have disastrous consequences for his health, including possible psychosis and suicide.

Judges also dismissed his calls for a judicial review of the case. Lawyers had challenged a refusal by Britain's chief prosecutor to allow McKinnon to be tried in Britain, which would have avoided any need for extradition.

"For the reasons set out in the judgment, the claims against the secretary of state and the Department for Public Prosecutions are dismissed," Lord Justice Stanley Burnton said in the ruling, according to the Press Association.

McKinnon, whose lawyers describe him as a "UFO eccentric" who used the Internet to search for alien life, is accused of causing the U.S. Army's entire network of more than 2,000 computers in Washington to be shut down for 24 hours in what U.S. authorities called "the biggest military hack of all time".

He was arrested in 2002 after U.S. prosecutors charged him with illegally accessing computers, including systems at the Pentagon and NASA, and causing $700,000 worth of damage.

McKinnon told Reuters in 2006 that he was just a computer nerd who wanted to find out whether aliens really existed and became obsessed with trawling through large military data networks for any proof that they might be out there.

He had used his own computer with a 56K dial-up modem at his London home with no password protection and somehow managed to evade every security measure the U.S. military had adopted.

If he is convicted by a U.S. court, McKinnon could face up to 70 years in prison.

Members of the British media and family and friends have waged a lengthy campaign to try to prevent McKinnon's extradition. His mother was angry at the latest setback.

"It's a disgrace, and they should be highly embarrassed," Janis Sharp told reporters outside the court. "This is from the Bush era, it is hold-over from the Bush era."

US President Barack Obama "would not want this to happen", she said.