In Dispatches: Lessons in Hate and Violence, secretly-filmed footage appeared to show a man hitting and kicking children during Qu'ran lessons at a school in the Markazi Jamia mosque at Keighley, West Yorkshire.
In a statement, West Yorkshire police confirmed that a 59-year-old man had been arrested after officers viewed the footage, but he was later released on bail pending further inquiries.
"We have recently become aware of a number of incidents of alleged assault at a mosque and just before the weekend were able to view edited footage of the alleged incident," said the force.
"One man has been arrested and released on police bail pending further inquiries. West Yorkshire police are receiving full co-operation from the Keighley Muslim Association who are working with us in support of the inquiry."
The Dispatches documentary has attracted criticism from some quarters for giving fuel to far-right groups, such as the English Defence League, and putting children's safety at risk. [Eh!? That's perverse Alice-in-Wonderland logic! In fact, it's not logic at all. What it is is an ideological ruse to deflect attention from the guilty (the Keighley mosque) to the besides-the-point (the EDL). There seems to be no escape from Islamic taqiyya.)
In the same programme, a preacher at an Islamic school in the West Midlands was depicted making offensive remarks about non-Muslims. The school has since confirmed plans to close early for half-term, apparently due to fears of reprisals from far-right groups.
However, a Channel 4 spokesman defended Dispatches, arguing that the programme was highlighting issues in the "public interest".
He said: "This investigation, which is clearly in the public interest, shows secret footage of numerous adults on different occasions teaching pupils as young as 11 years of age contempt for other religions and wider society. We stand by our investigation and think the programme speaks for itself."
In 2007, Channel 4 was forced to defend a Dispatches report on the views of Muslim extremists, after the programme attracted a formal complaint to Ofcom by West Midlands police.