Actress Keira Knightley has revealed that she took a female date to her school’s prom – but teachers told her she was “disgusting”.

The 29-year-old star, who is set to appear in upcoming Alan Turing biopic The Imitation Game, went to school while Section 28 was still in force, banning the “promotion” of homosexuality.

She told Variety: “I went to prom with my best mate, Emily.

“We both turned up an hour late, and I’d been filming Bend It Like Beckham, and I turned up in leather pants and a crop top, and she was a model for a while, and she’d been in Paris shooting something, and she turned up as the boy, so she had a black tie with ripped jeans on, and everybody else was completely dressed up, obviously, in that kind of finery.

“One of the teachers took us both aside and said we were never going to come to anything if we didn’t know how to dress appropriately for events like that. So that was my prom. We had a great time!”

“We had our picture taken underneath the thing, and she’s kissing me, and we were told that that was disgusting.

“Our photograph, though, wasn’t allowed — you know when you get up and, I don’t know if this is in America, but you collect all the photographs of prom and you buy whatever ones you want.

“Ours wasn’t allowed to be displayed on that because it wasn’t appropriate.”

Her Imitation Game co-star Benedict Cumberbatch recently rebuffed claims that the film disproportionately focuses on the gay codebreaker’s brief engagement with Knightley’s character, saying: “There is no heterosexuality expressed in the film.”