Mark Daly spent months working as a policeman in Manchester. His fellow officers were unaware that their colleague was, in fact, an undercover journalist who was trying to discover if racism lurked among their ranks.
By Mark Daly
Reporter, The Secret Policeman
I was running late and only had an hour and a half before I was due to start my afternoon shift. I planned to drop into my flat, pick up my uniform and head straight out to Hazel Grove Police Station in south Stockport.
I pulled into my drive, switched off the ignition of my battered old Astra and got out. I collected my bags and closed the boot.
Then a Peugeot 309 headed towards me. It screeched to a halt and blocked any escape routes for me or my vehicle. Two officers got out.
I knew the game was up.
"I am arresting you on suspicion of obtaining a pecuniary advantage by deception. You do not have to say anything..."
I only half heard the caution the detective reeled off, but the words were more than familiar to me. Because, for the past seven months, I had been leading a double life.
I am a BBC undercover journalist and 18 months ago I began the application procedure to join Greater Manchester Police.
In 1999 the Macpherson Report branded London's Metropolitan Police institutionally racist. The report, which followed the Met's failure to successfully prosecute a gang of white youths for the murder of Stephen Lawrence, found ethnic minorities in Britain felt under-protected as victims and over-policed as suspects.
The year before, the then chief constable of Greater Manchester Police took the bold step of admitting that his own force was institutionally racist.
We wanted to see what steps were being taken to eradicate this. But more importantly, we needed to see if they were working.
The only way we could find out what was really happening was to become a police officer - asking questions openly as a journalist would not have uncovered the truth.
Working undercover using the latest hi-tech covert filming equipment meant I could expose any of my fellow officers who held racist views or behaved in a racist manner.
And on 27 January this year, I had my first day of training as PC 2210 Daly. After five months of intensive training I was, for eight weeks, a fully operational PC working the beat.
I believe that at no time did my position as a journalist undermine or affect the way I carried out my duties with the public as a police officer.
But seven months later, after my arrest, I was taken to a police station in Didsbury, south Manchester, just a few hundred yards from my flat.
Standing there in front of the custody sergeant, in my summer shorts, a million things whizzed through my head. How did this happen? Did someone find one of my covert cameras? How could they have found me?
My cell contained a wafer-thin mattress set on a raised bench. The walls were whitewashed but stained with graffiti and God knows what else. The room was about eight feet by six, with a small toilet in the corner.
The smell of urine filled my nostrils.
With all the time in the world, I began to think of my colleagues, who by now would have known they had been betrayed by one of their own.
It is the most heinous act an officer could do. You never turn your back on a colleague.
There is a special camaraderie between police officers, like a brotherhood. I can only just begin to understand how they must have felt then.
Police forces are attempting to tackle racism
After a night in the cell, and hours of interrogation, I was released on police bail for three months.
In my time within the police, I encountered dozens of probation officers and senior officers, most of whom do their job with the highest of professional and ethical standards. I make no attempt to tar all officers with the same brush.
But the covertly filmed evidence against some of these men - and the allegations are not confined to GMP officers - is compelling.
What I found was a police service trying very hard - and failing - to put its house in order.
It was at the Police National Training Centre in Warrington, where trainees from 10 forces in the North West and Wales spend 15 weeks, that much of my material was garnered.
The extremity of some of the racism I encountered from these recruits beggared belief.
The majority of the officers I met will undoubtedly turn out to be good, non-prejudiced ones intent on doing the job properly. But the next generation of officers from one of Britain's top police colleges contains a significant minority of people who are holding the progress of the police service back.
Racist abuse like "Paki" and "Nigger" were commonplace for these PCs. The idea that white and Asian members of the public should be treated differently because of their colour was not only acceptable for some, but preferable.
I had become a friend to these men. They trusted me with their views. And they believed I was one of them.
I operated under strict guidelines. I was not allowed to make racist comments or incite anyone to do or say anything which they wouldn't have otherwise said or done. But I had to laugh at their jokes and behave like a dumb apprentice. I said I was eager to hear other people's views in order to form my own. And they didn't hold back.
There is no doubt that this investigation will come under massive scrutiny from the police and the media - and rightly so.
The police say they are open and accountable to public scrutiny. If this is the case then they should welcome this investigation.
And if the police have nothing to hide, then they would have nothing to fear.
The decent officers out there, I hope, will support what I have done.
But there is no doubt that this programme will make some very uncomfortable viewing for the police service and the racists still in it.