THE PARENTS of a Scots computer expert who faces extradition to the US for hacking into the Pentagon and other military installations have claimed that he has been threatened with rape in an American prison even before his trial.

Gary McKinnon's family revealed their fears after his solicitor, Karen Todner, last week appealed to the home secretary, Jacqui Smith, to ensure that he can serve out any prison sentence imposed at a court in Virginia in a UK prison after he goes on trial for a crime described by American prosecutors as the "biggest computer hack of all time".

McKinnon, 42, who was born and brought up in the Maryhill area of Glasgow before his mother, Janis Sharp, and father, Charlie McKinnon, divorced, suffers from Asperger's syndrome, which his legal team hope Smith will take into account after he recently lost his appeal against extradition to the European court of human rights.

Sharp, 59, is convinced the US authorities will treat him as a terrorist suspect. The offences he is accused of could see him serving up to 70 years in a federal penitentiary. She told the Sunday Herald: "If Gary goes to the US, he will not get a fair trial because they see him as a cyber-terrorist.

"How can you trust a country that has Guantanamo Bay and thinks water-boarding simulated drowning is not torture? I am incredibly distraught and terrified of my gentle son going to any US prison because it sounds like something out of your worst nightmares.

"Some people who say they are from the US military have written to our website with rape threats. We are really scared that Gary will finally be extradited."

In 2002, the family's world caved in when Gary was arrested by Metropolitan Police cyber-crime officers at the flat he shared with his then girlfriend in Wood Green, North London. The systems administrator and UFO spotter had gained access to the world's most secure military installations using her £150 computer and dial-up connection.

According to the US, they included the US army, navy, air force and Pentagon computers and Nasa. Prosecutors estimate the damage was worth $700,000 and made US navy computers inoperable in the months following the September 11 terrorist attacks.

He was detected after attempting to download a black-and-white photograph, which he claimed represented an alien spacecraft, from a Nasa computer in the Johnson Space Centre in Houston, Texas, which he thought was evidence of a UFO cover-up conspiracy.

Sharp, who lives with her second husband, Wilson, 60, in Enfield, Middlesex, said: "You shouldn't be able to extradite someone for computer hacking. The Pentagon's computer security wasn't even as good as a bank, and had a real terrorist gone in anything could have happened."

Sharp and her ex-husband organised a protest outside the Home Office last week to put further pressure on Jacqui Smith to review the 2003 Extradition Act. Critics say the treaty is one-sided, with America able to demand UK citizens be extradited to the US, but Britain unable to demand the extradition of US citizens, as only London, and not Washington, has signed the treaty. Those opposed to the treaty also say it is increasingly being used to extradite white-collar criminals rather than its primary target of terrorist suspects.

Sharp added: "The UK government should not sell its citizens down the river by subjecting us to an unfair treaty America doesn't answer to. The UK is completely run by America and they can take Gary whenever they like."

Charlie McKinnon, 63, who lives in Glasgow, claimed US prosecutors want his son more than Abu Hamza, the notorious Finsbury Park hate cleric who is wanted on charges of inciting terrorism and whose appeal is being considered by the European court of human rights.

He said: "They want Gary more than Hamza due to the trouble he's caused them. There's been little public sympathy. We have to keep going and try everything, but we are running out of options.

"I want assurances from the home secretary that if he is extradited, he will be immediately brought back to serve his time here after the trial. Everything's in the hands of the Americans, and my fear is they are going to use him. Gary never thought it was going to go this far and is distraught."

Todner said: "We told the home secretary that the Dutch and Israelis have an arrangement that, if any of their citizens are extradited to the US they are immediately repatriated to serve their sentences."

The Home Office confirmed that Smith is examining the lawyer's application.