Computer hacker Gary McKinnon has refused to undergo further medical tests by a Home Office-appointed expert as he fights extradition to the United States, his mother said today.

Janis Sharp said her son would not undergo a final psychiatric examination before the Home Secretary decides whether to order his extradition.

The case will return to London's High Court on Tuesday "in anticipation of an imminent Home Office decision", a family spokeswoman said.

At the last court hearing on July 5, judges were told Theresa May was "close" to making a decision.

But she was "personally concerned" that medical experts instructed by her department had not been permitted to carry out an examination to help her decide whether McKinnon would be at high risk of committing suicide if removed.

McKinnon's supporters claim the Home Office-appointed expert, Professor Thomas Fahy, has no experience in uncovering suicidal tendencies in Asperger syndrome patients.

He has already been assessed on "at least six different occasions by six independent specialists", they said.

Ms Sharp said: "Gary's ordeal has gone on for far too long.

"The Home Office should accept the very clear and incontrovertible evidence provided by the country's leading psychiatric experts in this field.

"It's time to make the right decision and end Gary's torment of extradition.

"When he's fit and ready, as we have said all along, the CPS could try him in this country for his foolish acts that happened over a decade ago."

She went on: "No one has ever been extradited from America to the UK for conduct that took place in America so why is Britain extraditing British citizens to the US for actions undertaken on British soil?

"It's cruel, unnecessary, and for years has blighted not just Gary's life but mine and our family's too.

"The victims of extradition include the friends and family of those facing extradition.

"Parliament passed a motion in December for treaty change to take place as pledged pre-election by the coalition. Hopefully this will be implemented soon."

Ms Sharp added: "Gary has endured 10 years of mental trauma and has lost 10 years of his youth. We so need a good end to this.

"I'm sure that Theresa May will do what's right, and make a just and compassionate decision now and allow Gary to begin to regain some of the life he has lost."

American officials have demanded that Mr McKinnon is tried in the US despite expert opinions obtained by his legal team warning that his mental condition could lead him to commit suicide if extradited.

Assessing the level of risk is crucial to the Home Secretary's decision on whether to allow extradition to go ahead.
The US authorities want Mr McKinnon, from Wood Green, north London, to face trial for hacking into military computers 10 years ago.

The case was described by Hugo Keith QC, appearing for the Home Secretary, as "this rather vexed and perhaps totemic case" with important implications for Britain's extradition laws.

McKinnon faces up to 60 years in jail if convicted of hacking into Pentagon and Nasa computers between February 2001 and March 2002.

The 46-year-old, who suffers from Asperger syndrome - a high-functioning form of autism - was first arrested in 2002.

He admits to what one US lawyer called "the biggest military computer hack of all time", but claims he was looking for evidence of UFOs.

At the High Court hearing earlier this month, the judges heard that the joint current view of two psychiatric experts - Professor Thomas Fahy and Professor Declan Murphy - was that Mr McKinnon's suicide risk was "moderate".

Mr Keith said Prof Murphy had examined Mr McKinnon in November 2009 and said the risk was high and he would require one-to-one observation to avoid a serious suicide bid, but his latest assessment was that the risk could be managed.

Dr Jan Vermeulen, one of the medical experts appointed by Mr McKinnon's advisers, was now asserting for the first time that the hacker was unfit to plead and stand trial.

There was lack of supporting evidence for that view, but a fresh examination of Mr McKinnon could lead to a resolution of the differing views, argued Mr Keith.

If Mrs May rules in favour of extradition, the McKinnon case is likely to remain far from over as fresh judicial proceedings could be triggered by that new decision.