Rita Ora has revealed that she kept forgetting her lines while filming her scenes in Fifty Shades of Grey.

The RIP singer, who landed the role of Christian Grey's (Jamie Dornan) sister Mia Grey in the big-screen adaptation of EL James's novels, said that she had to wear an earpiece while filming so somebody could feed her the lines.

She told Access Hollywood: "I had to have someone in my ear on set telling me what to say before I said it because I was honestly like so nervous I forgot everything that I had learnt."

The star added that her co-star Dakota Johnson, who plays Anastasia Steele in the film, helped her get over her first-time acting nerves.

She said: "She's [Dakota is] a great friend of mine and she really eased me, and she was really nice to take care of me."

Ora added about director Sam Taylor-Johnson's adaptation: "The movie is as visually close as it can be [to the book]. I think the actors are phenomenal in this and I'm just kind of honoured to be on the same wavelength as them.

"This being my first movie, it's pretty awesome."