UFO hacker Gary McKinnon, whose mother Janis Sharp lives in Brookmans Park, has refused to undergo a further assessment of his suicide risk in his battle to avoid extradition to the USA.

Ms Sharp told the Welwyn Hatfield Times that he had “no option” but to refuse as the Home Office-approved doctor, Professor Fahy, “does not have expertise in Asperger’s”.

She said Mr McKinnon had already undergone examinations by six doctors and had been assessed on countless occasions – she said he had already seen three experts this year.

She said: “The Home Office has appointed Professor Fahy, yet Professor Fahy, although eminent in his field, does not have the expertise in ASD which is required to uncover suicidal risk or unfitness for trial in Asperger’s syndrome patients.

She added that if anyone but an Asperger’s expert were to undertake the tests they could miss vital signs.

“Gary will say the fires of hell are burning inside but to look at him you couldn’t tell”, she said.

Ms Sharp said the family were “resting on the extensive medical evidence already submitted to the Home Secretary”.

And she issued a plea for Theresa May to “make her decision based on the existing compelling evidence as soon as possible”.

Mark Lever, chief executive of the National Autistic Society agreed with Mr McKinnon’s refusal to undergo the test.

He said: “Asperger syndrome is a complex condition and it would be impossible for anyone without specialised training to fully understand its impact.

“If Gary is forced to undergo an assessment that doesn’t take account of his needs and he is consequently extradited, it could have very serious and potentially tragic ramifications.”

He added: “This situation has dragged on for over 10 years – and the stress of this in itself will undoubtedly have had a negative impact on Gary’s mental health.

“The Home Secretary must urgently take the necessary steps to recognise Gary’s needs.”