The horrors Gary McKinnon faces in jail - by a man who knows

 A member of the NatWest Three, who spent two years imprisoned in Texas for his alleged role in the Enron affair, has said he fears that computer hacker Gary McKinnon faces an ordeal of "terrifying brutality" if he is extradited to the United States.

McKinnon, 45, suffers from Asperger's syndrome, a form of autism. His family have been fighting his   exradition for nearly a decade since he admitted hacking into Pentagon computers in search of evidence of UFOs.

Mulgrew knows what he's talking about. Following his controversial extradition to the US in 2006, he was jailed in a remote prison near the Mexican border of Texas where he never encountered a guard. "They policed the edges of the place. The inmates were in charge of the rest."

Mulgrew recounts his experience in a book Gang Of One, serialised in the Mail on Sunday.

His problems began the moment he and the other members of the NatWest Three - Giles Derby and David Bermingham - disembarked in Houston, Texas in 2006.

They were led from the plane to a large office within the airport where FBI agents and marshalls, smiling and laughing, were gathered.

"You! Stand up and come with me," a marshall called Dave shouted at Mulgrew.

Mulgrew followed him into a windowless room. "Face me!" said Dave, making up for his lack of stature - he was considerably shorter than Mulgrew's 6ft 2in - with his bark.

"Don't you fuckin' look at me," Dave went on. "Did you fuckin' look at me?"

Another officer, wearing sunglasses, butted in: "He fuckin' looked at you boss."

"Did you fuckin' look at me," Dave asked again.

"No, er, yes ... I mean, I didn't," Mulgrew replied.

"Don't fuckin' talk to me like that!" Dave screamed, before issuing his 'rules'.

These were that Mulgrew must answer only 'No sir' or 'Yes sir' to any questions and NEVER 'eyeball' him. Any other comment at all, or any eyeballing, would be deemed an attempt to escape. And any attempt to escape would mean an extra five years' jail.

Mulgrew was then told to remove all his clothes and prepare for a strip search.

While Dave pulled on surgical gloves and did his thing, Mulgrew writes, "I thought of England. Of Tony Blair [who had failed to stop the extradition]. I remembered I heard him saying how we would be well treated."

The body search completed, Mulgrew was ordered to turn round.

"What the fuck are you smiling at?" Dave asked. "You think I'm funny, English boy?"

Eventually Mulgrew was allowed to get dressed. "Git your boxers back on," he was told, as Dave stormed to the door, adding: "Let's get these British faggots locked up."

Mulgrew became used to being addressed as 'Boy" by American law enforcement officers.

When he arrived at Big Spring prison in Texas, he was met by a guard with a clipboard who asked his name.

"Mulgrew, Mulgrew sir. My name's Mulgrew."

"What's that you say" the guard responded. "Mildew, Mildew, you said? There ain't no Mildew ... There's a MULGREW here. Is that what you meant to say, boy?"

Inside the jail, Mulgrew was shocked to discover that he would be spending his sentence not in a small cell with one or two other inmates, but in a 80ft dormitory crammed with yellow bunk beds and small lockers.

"This wasn’t punishment," writes Mulgrew, "it was an experiment: the Big Brother house with wall-to-wall psychos."

In the two years that followed, Mulgrew witnessed a prisoner being so brutally attacked he is not sure to this day whether the man died or not. He had to avoid the Aryan Brotherhood - skinheads who sought to recruit him as one of the few white men in the jail. He never saw a prison guard.

"What awaits Gary McKinnon if he is actually extradited to the US is unthinkable,’ said Mulgrew, now 49, told the Mail on Sunday in a separate article. "Why subject a British citizen to such stress and degradation when they could and should be dealt with here in the United Kingdom?"

• 'Gang Of One' by Gary Mulgrew is published by Hodder & Stoughton. The Mail on Sunday will publish a further extract next weekend.

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