On January 15 last year Channel 4's Undercover Mosque documentary showed preachers at mosques in the West Midlands urging the killing of homosexuals and lapsed Muslims.

Two weeks later anti-terror police arrested nine men on suspicion of involvement in a plot to kidnap and behead a British soldier home on leave in Birmingham. Five were convicted later.

The raids were followed by widely reported claims from one of those released after questioning that Britain had become “a police state for Muslims” and that those arrested were suffering trial by media. The atmosphere in Birmingham at the beginning of 2007 was febrile. West Midlands Police found themselves expending as much effort defusing community tensions as investigating the kidnapping plot.

As the fear of disorder receded, however, they began an investigation into the Channel 4 programme — obtaining a court order to seize hours of footage. That inquiry quickly shifted from looking at the preachers to examining the actions of the film-makers.

Prosecution lawyers decided there was insufficient evidence to press charges but complained publicly that the programme had been heavily edited and distorted the views of the preachers.

West Midlands Police took its concerns about the programme to the broadcasting watchdog. In a statement to Ofcom, the force revealed that concern “with matters of public reassurance and the reduction of crime and disorder in all communities in the West Midlands” lay behind its decision to turn on the programme rather than the extremists it had exposed.

The situation echoed the wrong-headed policing of Finsbury Park mosque, Abu Hamza al-Masri's North London base, where jihad was preached and organised for seven years under the noses of the Metropolitan Police.

Even after the mosque was closed in an anti-terrorist raid in 2003, the Met spent £874,000 protecting Abu Hamza and his acolytes as they preached on the street outside.

The commander in charge told The Times that moving Abu Hamza and his followers on would have exacerbated “a difficult situation”. In other words, a decision was taken to pander to the hardliners because of the fear that they might stir up trouble.

The media has revealed repeatedly the strong current of fundamentalism that runs through many supposedly moderate Muslim groups. And they have been made to pay for doing that through legal actions, vilification of reporters online and, in the case of Channel 4, a criminal inquiry.

Hopefully, such shooting of the messenger will soon end. The Government is investing hundreds of millions to counter radicalisation in the Muslim community, and among counter-terrorism agencies emphasis is on moving “upstream” to stop young men being groomed for terrorism. The authorities have finally realised that what the media has been giving warning about for years is true: unchecked extremism breeds terrorists.

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