Dispatches: Lessons in Hate and Violence, Channel 4, screened on 14 February.

Television can’t get enough of “preachers of hate” radicalising young Muslim boys, and this week’s Dispatches on Channel 4 was happy to feed the public appetite.

Undercover filming showed boys at a respected Islamic secondary attending assemblies where speakers incited hatred of non-believers and poured scorn on the corrupting influence of Western society.

“Hindus drink the piss of a cow,” the boys are told by one young speaker (an older pupil who, according to the school, was subsequently expelled).

Someone with less than a fistful of beard is worse than a snake, a visiting speaker tells the students. Trousers must hang above the ankles or boys risk double detention. Hairstyles must be Islamic. Music and dancing are bad.

So far, so prejudice-confirming. But what is captured on film at Darul Uloom Islamic High School in Birmingam, while clearly worrying in an inspected school praised for its tolerant outlook, is hardly the stuff of nightmares.

More shocking to teachers or parents are the scenes in the Markazi Jamia mosque in Keighley, west Yorkshire.

Boys attending instruction classes on the Koran are apparently kicked, spanked and hit by their teacher as they read aloud.

Ann Cryer, former MP for Keighley, tells reporters: “We wouldn’t allow this to happen to white kids going to Sunday schools.” Quite. There would be an outcry.

The mosque said this week that staff would receive child-protection training following the expose. Some classroom-management training probably wouldn’t go amiss, either.

Scenes in which young boys are attacked by older pupils when they are left alone in the same room are hard to watch, but it seems unfair to single out the mosque. Leave a camera in a room full of unattended boys in a mainstream secondary and there is a strong chance of some argy-bargy.

But this footage is balanced by scenes in the Muslim Educational Centre of Oxford, where children are taught tolerance.

The contrast only serves to make you feel sorry for parents looking for a decent Muslim education for their children - without exposing them to extremist views or violent teachers.

If they can’t rely on even the most respected Muslim schools not to allow racist and intolerant speakers in their school assemblies, who can they trust?