After a racism row on BBC TV show Question Time, actor Laurence Fox has launched another salvo in the diversity debate - this time targeting movie director Sir Sam Mendes.

Mr Fox, who won fame starring in episodes of Morse sequel Lewis as DS Hathaway, last week found himself in the spotlight when audience member Rachel Boyle called him 'a white privileged man' for denying the Duchess of Sussex has been unfairly treated by the British media due to being mixed race.

READ AGAIN: Lewis star Laurence Fox stands by Question Time 'racism' comments

The actor defended himself by suggesting that Ms Hill was behaving in a racist fashion by calling him a white privileged male.

Oxford Mail:

Now the actor, who is also embarking on a career as a musician, has prompted more controversy by questioning the motives of former Magdalen College School pupil Sir Sam Mendes, who lives in Oxfordshire, for his portrayal of Sikhs in his First World War movie 1917.

Oxford Mail:

Speaking on James Delingpole's podcast (as reported on the Mail Online), Fox said the inclusion of actor Nabhaan Rizwan distracted from the plot, which focuses on a British regiment.

He made the point that Sikhs fought alongside British forces as opposed to in the same units.

READ MORE: 1917: Director Sam Mendes talks about bringing war movie to life

Mr Fox said: "It's like, 'There were Sikhs fighting in this war'. . . okay you're now diverting me away from what the story is.

"There is something institutionally racist about forcing diversity on people in that way."

Mr Fox praised the performance of Mr Rizwan himself, saying it was 'great' but said the inclusion 'did sort of flick me out of what is essentially a one-shot film because it's just incongruous with the story'.

Oxford Mail:

Sikh soldiers were present at some of the conflict's bloodiest battles, including the Battle of the Somme in 1916.

The film director received a knighthood in the New Year's Honours.

He is best known for James Bond movies Skyfall and Spectre and dramas such as American Beauty.

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The movie 1917 is dedicated to the director’s grandfather, as well as the others who served in the armed forces in the Great War, which brought with it the weight of responsibility of honouring their sacrifice.

Oxford Mail:

“It was not just familial responsibility but also generational,” said the director earlier, who also plays cricket for Oxfordshire Over 50s and once turned out for Shipton-under-Wychwood at Lords in the final of the Village Cricket Cup.

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He added: "You have a responsibility, it sounds corny, to the men who fell in the war and the generation that was lost."