PlayA Briton accused of the "biggest computer hack of all time" has lost his appeal against extradition to the US where he could face a life sentence.
The Law Lords announced their ruling on a bid by Gary McKinnon to quash an extradition request granted to the US authorities in 2006.
McKinnon, who has never been charged in Britain, admitted gaining access to 97 US military and Nasa computers from the London home of his girlfriend's aunt.
He lost his case at the High Court in 2007 and went straight to the the House of Lords where his barrister David Pannick QC said extradition would be an abuse of proceedings.
A statement by solicitors for McKinnon, who was not at the House of Lords, said: "Gary McKinnon is neither a terrorist nor a terrorist sympathiser.
"His case could have been properly dealt with by our own prosecuting authorities.
"Instead, we believe that the British Government declined to prosecute him to enable the US government to make an example of him.
"American officials involved in this case have stated that they want to see him 'fry'.
"The consequences he faces if extradited are both disproportionate and intolerable and we will be making an immediate application to the European Court to prevent his removal."
McKinnon has been warned by the US authorities that he faces a life sentence rather than a couple of years in jail unless he agrees to plead guilty and accept extradition.
Without co-operation, said the authorities, the case could be treated as one of terrorism, which could result in up to a 60-year sentence in a maximum-security prison should he be found guilty.
It had been reported that US prosecutors had wanted to "see him fry".
McKinnon, 42, a Glasgow-born self taught IT expert, says he was motivated by curiosity and was looking for evidence that the US government had information on UFOs. He described his exploits as "ridiculously" easy.
After a previous hearing, he said: "I was amazed at the lack of security and the reason I left not just one note but multiple notes on multiple desktops was to say 'Look, this is ridiculous'.
"My intention was never to disrupt security. The fact that I logged on there and there were no passwords means that there was no security."
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