It won star Timothy Spall an acting prize at the Cannes film festival and was nominated for four Oscars. But the Mike Leigh biopic Mr Turner has nevertheless been named 2014’s most complained-about film by the British Board of Film Classification (BBFC), thanks to a scene in which Spall “vigorously” clenches his clothed buttocks.

The UK ratings board said 19 people wrote in over the brief shot in the 12A film, compared to a dozen for the second most-complained-about film, Steve McQueen’s Oscar-winning race drama 12 Years a Slave.

In Leigh’s film, Spall’s “clothed buttocks are seen clenching vigorously, before the scene cuts to a close-up of his face and his thrusting head and shoulders”, according to the board, which said it considered the shot acceptable in a 12A film “given the lack of nudity, the relative brevity of the scene and its importance in terms of narrative”. The annual BBFC report, which detailed the classification of more than 950 films in UK cinemas last year, also described the 19 complaints as “a very low figure for most complained-about film”, and “a tiny proportion of those who will have seen it”.

The dozen complaints about 12 Years a Slave centred on a rape scene involving a female slave. The BBFC report covers the period from January to December 2014.

The Tom Cruise action thriller Jack Reacher was the most complained about film of 2013, with 26 complaints about the 12A rating the film had received. Generally, the British public appears to be complaining less as time goes by: the period horror film The Woman in Black drew 134 complaints about its 12A certificate a year previously, while four years earlier the similarly-certified superhero thriller The Dark Knight attracted more than 300 complaints.