Mr Turner is the most complained about film of the past year due to Timothy Spall’s 'bottom-clenching'

'Turner’s clothed buttocks are seen clenching vigorously, before the scene cuts to a close-up of his face and his thrusting head and shoulders'

Timothy Spall during the filming of ‘Mr Turner’, in which he took the title role

Timothy Spall’s portrayal of painter JMW Turner on the big screen earned him rave reviews and an acting award at the Cannes Film Festival. But it appears his “clenching” buttocks in Mr Turner also drew the public’s disapproval, surprisingly making it the most complained about film of the past year.

Each year, the British Board of Film Classification (BBFC) compiles a list of the films that drew the most correspondence from the public, which is usually dominated by horror or violent action movies.

However, in 2014, director Mike Leigh’s historical drama about the life of one of Britain’s best loved painters drew 19 letters of complaint. The BBFC admitted it was a “very low figure” but said it was the highest number of complaints received about a single film during the year.

The Independent hailed the film and described Spall’s portrayal of the artist as “magnificent”. Yet one scene in which Turner forcibly has sex with his housekeeper was deemed to have overstepped the mark. According to the BBFC report, “Turner’s clothed buttocks are seen clenching vigorously, before the scene cuts to a close-up of his face and his thrusting head and shoulders”.

There is no nudity and Turner appears distressed; the scene ends with him sobbing “almost in an exhibition of self-loathing,” the report said, adding it was important to the story. “Context is central to the question of acceptability of film and video context.”

The BBFC said the film remained acceptable as a 12A certificate and pointed out that 19 complaints made up only a tiny proportion of those who had seen it.

The film was director Leigh’s most successful film and was hailed by critics. But experts were left bemused when Spall missed out on both Oscar and Bafta nominations for best actor after securing the top award at Cannes in 2014.

The sex scene between Turner and housekeeper Hannah Danby, which drew the complaints, was invented, Leigh revealed. “We know she was very loyal to him,” he told film site Crave Online. “We have invented the sexual relations between them but it felt very right to us.”

The most complained about film in recent years was Batman: The Dark Knight, starring Christian Bale and Heath Ledger. In 2008 the action film drew more than 300 complaints over the level of violence in a 12A-rated film.

More recently, The Woman in Black, a horror film starring Daniel Radcliffe received 134 complaints saying it was “too dark and unsettling”. Black Swan was also the focus of grievances from the public, with many surprised that it was a psychological thriller rather than a gentle film about ballet.

This year, 12 Years a Slave, rated a 15 certificate, was the second most complained about film, drawing 12 complaints about the violence, especially the sexual violence, in the true story of a free man forced into slavery in the American South.

Surprisingly, film fans wrote to the BBFC in 2013 to complain that there was not enough violence in some films. The classification body received letters over The Hunger Games and A Good Day to Die Hard, which were both cut by the producers to get a 12A rating after consultation with the BBFC.

The same year, children’s classic The Railway Children received its first ever complaint, more than four decades after it was released.