Undercover with 'the firm'

Hooligans are on the rampage, smashing up everything in their path. How do you capture it on film? Undercover producer Jason Williams describes the dangers he faced in the making of BBC Two's Hooligans programme.

Filming undercover, whether it is exposing disreputable business men or mixing with hooligan gangs can be exciting, but also very dangerous.

Exciting because of the complete adrenalin rushes it gives you and dangerous because of the fear of exposure.

The subject of football was rarely discussed amongst hooligans

Months of hard work and research could be wasted if you fail to convince someone you are who they think you are. There is also the threat of being the victim of a violent attack.

Preparation is vital. I love football and know enough about the game - so that was not a concern.

In fact I came to learn the subject of football was rarely discussed amongst hooligans. On match days, their preoccupation with finding rival firms often took centre stage.

Followers of fashion

It was looking the part that concerned me more. To pass as a football hooligan I had to look like one and that meant wearing the right kind of gear.

There is a fascination among football hooligans with designer labels such as Lacoste, Burberry, Aquascutum and in particular with Italian label Stone Island.

Having trawled the designer shops, I felt confident that I would at least be accepted as a "lad" - a term football hooligans use amongst their peers.

Unfortunately for them, their taste in clothes can be their undoing. I was turned away from a pub in Cardiff on one occasion.

Ironically, it was not for wearing a football shirt, but for wearing Stone Island because of its association with hooligan culture.

The town is home of Cardiff City's notorious "Soul Crew", one of the top hooligan firms in Britain. I was there on the opening weekend of the season for the Charity Shield.

Being an Englishman, I knew it would be difficult to convince them I was one of their own. But somehow my Welsh accent passed the test.

Jason discreetly checks the footage he has filmed

Armed with my secret camera, I had been with them through the day as they searched for trouble.

We roamed the back streets of Cardiff looking for Manchester United fans, and trying to avoid the police.

"Can you smell that?" one said looking straight at me, "I can smell ****ing English."

For an instant, I thought my cover was blown. But luckily his comments were not aimed at me.

There was no more trouble that day. I was able to leave without being caught out by this violent group.

No one likes them

But in my opinion, by far the most dangerous football firm in Britain is Millwall. I have travelled undercover to eight matches, home and away, with them this season.

They had not come all this way to take in the sea air.

In March 2002, we were expecting trouble at their game in Portsmouth. Earlier in the season I had witnessed a mob of Millwall lads attack a Pompey fan outside The New Den in South-east London.

Walking to the ground I could see that many of Millwall's hardcore hooligans had made the trip. They are known as "The Bushwhackers", and they had not come all this way to take in the sea air.

Stewards were searching everyone entering the ground. I became concerned for my safety.

I have been searched by police officers and stewards before. Trying to explain who you are and why you are carrying a secret camera tends to lead to a lot of questioning.

The last thing I wanted was to be searched in front of Millwall's mob. Casually I moved to the back, and slipped away down a side road before the police had an opportunity to usher everyone into the ground.

I waited until kick-off, as by then the stewards and police were inside. I paid my entrance fee and walked through the turnstile.

Another close escape.