Gary McKinnon stands accused of becoming the most accomplished computer hacker in history by crashing the United States army network, but claims only to have been pursuing a fascination with aliens.

The 42-year-old unemployed systems analyst, who broke into US military computers from his bedroom in Wood Green, North London, faces at least ten years in a US jail. He has always claimed that he was seeking information on UFOs and aliens.

He lost his final appeal against extradition yesterday after the law lords were told that he rejected a plea bargain in which he was offered a shorter prison sentence of three or four years in return for pleading guilty. The law lords dismissed Mr McKinnon’s claim that threats made against him by US prosecutors amounted to an abuse of process and refused to quash extradition procedings against him.

Mr McKinnon admits accessing 97 US military and Nasa computers. US prosecutors also allege that he shut down and rendered inoperable 300 computers at a US navy weapons station at a critical time, immediately after the terror attacks of September 11, 2001. His only hope is to persuade the European Court of Human Rights to put a “stay” on proceedings, pending consideration of his case.

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Mr McKinnon said last night that he was sorry for his actions but felt the US reaction was disproportionate. He described his actions as “misguided” but said it felt “like a moral crusade”. He said he had not damaged the computer systems, as the US claimed, but had highlighted security problems.

He told BBC Radio 5 Live: “I’m extremely sorry I did it, but I think the reaction is completely overstated. I should face a penalty in Britain and I’d gladly do my time here. To go from, you know, perhaps a year or two in a British jail to 60 years in an American prison is ridiculous.”

Karen Todner, his solicitor, 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 law lords heard that under the plea bargain he would serve six to twelve months and then be returned to Britain to serve the rest of his sentence. Lord Brown of Eaton-under-Heywood said that, in all, he might serve eighteen months to two years. However, if he were extradited and convicted, he might expect a sentence of between eight and ten years, possibly longer, and would not be repatriated at all.

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