Everyone knew Tony. He was a mate; they called him "Toe". A bit of a daft Paddy, but all right. His hair was sufficiently short, his language convincingly bad, his reading habits reassuringly tabloid. He hated students and posh people like a proper bouncer should, and he seemed as if he was into drugs like the rest of them.
Toe trained in the gym with Nottingham's most infamous drug-dealer and doorman, 20-stone Wayne Hardy. It was his seal of approval. The only small problem with Toe was that as well as working on the doors he was working for ITV's World In Action. Under his shiny Everlast bomber jacket he was wearing a concealed camera, with which, in the last year, he has shot more than 200 hours of material: evidence sufficient to blast Wayne, his entire gang and the myth of the honest bouncer to kingdom come.
"It wasn't just a case of following these bouncers, and getting friendly with them," says McIntyre. "I had to become one of them. We chose Nottingham because it is perceived as a normal city - it hasn't got the gun culture of Liverpool or Manchester - yet the violence and drug-dealing are almost as serious."
A flat was rented for "Tony Hearns". It was carefully chosen. Not too flash, but not too down-at-heel, either. McIntyre cut his hair and abandoned all his normal clothes. He swapped his suits and Gap shirts for pounds 150 Oakley shades, black jeans, and a black jacket. "It's a uniform, like the City," he says.
The office was the gym, a place where bouncers do their day-work, and where Wayne held court. "I knew I had to befriend Wayne. He was at the centre of the ring. And it was in the gym. The whole body culture thing with bouncers is astonishing; it's outrageously heterosexual, but with an intense `body beautiful' feel to it. Everything depends on how big your muscles are."
As a former international canoeist, McIntyre was familiar with working out; he was fit, and looked the part. "But I was nothing compared to these 18-stone bouncers. They were enormous."
Slowly, with a mixture of flattery ("I told them how huge they were, made them feel good about themselves") and feigned enthusiasm for the job, McIntyre entered Wayne's world. He discovered a cash-run universe of muscle-enhancing steroids, drug-taking, theft and violence, a world where you boasted about hit-and-run jobs, and how well you beat up your girlfriends. If you were unlucky enough to have been inside for a spell, you boasted about how you beat up your fellow prisoners.
McIntyre and his camera became privy to everything, from drugs deals to tips on how to do damage to a punter in a club: "You partially strangle them. If they call the cops, you're in the clear. The bruises don't come up for two hours." McIntyre shrugs. "People think if their kids go out, the bouncers will keep an eye on everything. But they're the main offenders."
To get work on the doors, McIntyre had to be convincing. "My Irish accent was a blessing; no one could tell what area or class I was from. If anyone asked me what I did before, I'd say I'd worked in security. Bodyguarding, that kind of thing. It worked.
It was like a signpost saying I was up for dodgy business."
But the strain was enormous. Over the past 12 months McIntyre calculates he exchanged upwards of 3 million words with Wayne and his mates. "If I had got four or five of them wrong in succession, at a time when it mattered, that would have been it. I would have been very seriously hurt." His brother Tadhg, a psychologist, has helped him cope with the stress involved in undercover work. He went through intense self-assessment programmes.
"They revealed I was using what's called Formula One concentration. It's the sort of mind-set Damon Hill has in a race. Your whole mind is focused on not getting it wrong. If you mess up for one second, the consequences are dire."
He developed some useful tricks, such as drinking from dark bottles. "I could pretend I'd finished, when the bottle was still completely full. There was no way I wanted to get drunk. I also took up smoking. Smoking is a great thing; it keeps people away from your body. I think it's a kind of Neanderthal fear of fire; if you wave a fag around, people keep away from you." Useful if you are concealing a camera.
There were still some bad moments. One day someone slapped him on the back and felt the camera. "He shouted out `Hey, Toe, what the hell's that?' I just said that I'd hurt my back in the gym, and I was wearing a support. Fortunately he believed me."
McIntyre got close to Wayne. "I was his protege, and I became his best friend, even his counsellor. He used to fantasise about beating up his girlfriend, and I'd talk him round. I wasn't going to be complicit to violence, so I used to talk him out of it. We got very close."
After a year working within the gang, and six months on the doors, it was time. "When I finally walked up to Wayne, surrounded by a Granada camera crew, it was like confronting your nemesis. I could see him struggling to recognise me. I was clean-shaven; I was in a suit, I had a tie on. As far as he was concerned I could have been wearing women's clothes. He gasped, in fact he almost laughed. He put his head in his hands, but you could see the thoughts running through his head. Here was Wayne, the big-time drug dealer, tripped up by the dumb Paddy he trained with in the gym."
Since then all hell has broken loose in Nottingham. Wayne has fled town and scores of bouncers have been dismissed; McIntyre is lying low, delighted to have abandoned his alter ego, although he has opted for a couple of counselling sessions to help him cope with the aftermath of Tony Hearns. "I won't miss him, and I won't miss the people I lived with for 12 months. I never liked them. I never liked their world. They were walking chemical warheads, souped up on steroids and drugs and human growth hormones."
Yet memories of Wayne's world will probably never leave him. "It's a parallel universe from the one I was used to. People treat you like you're another species. They blank you. A punter in a club said to me once, `You're just a doorman. You'll never be anything else. You're a nobody.'" McIntyre pauses. "But the club did tell me I was the most polite doorman they'd ever employed"n
The second part of Donal McIntyre's `World in Action' investigation will be broadcast on ITV at 8pm tonight.