Rihanna has joked she doesn't know why she likes Gwyneth Paltrow as she's "really jealous" of her.

The songstress collaborated with the Hollywood star's husband Chris Martin and his band Coldplay on track Princess of China. Rihanna and Gwyneth were photographed at the Grammys together after her performance with the British band, who have also covered her hit track We Found Love.

Rihanna is in awe of Chris' stunning wife, but has jokingly admitted she's not sure why.

"It's flattering. It's special to know that other musicians appreciate your music as well. To have a band like Coldplay - that was just surreal. The version that they did, if I love it, it's extra points.

"I know Coldplay. We collaborated together, worked in the studio and shot a video. I'm obsessed with [Gwyneth].

"Her body. I'm really jealous of her. I don't even know why I like her," she laughed in an interview with Australian radio show Kyle and Jackie O.

Rihanna is starring in Battle ship alongside Taylor Kitsch and Liam Neeson. Johnny Depp is famed for not watching himself back on screen, and after shooting her first movie, Rihanna can understand the Hollywood hunk's way of thinking.

"I could see how that could happen, I do, because it is awkward, especially because I hate to hear myself speak. I'll never listen to this interview ever. I'm serious, I don't even know why," she joked.

"But I see how that could happen for him. Listening to yourself on a voicemail, it's like, 'Ew!' [I think I sound] gross."

Rihanna has explained why she chose to star in Battleship. The 24-year-old star plays Petty Officer Cora Raikes and loved the gritty role.

"I think it was a few things. I love that it wasn't a typical role, it wasn't close to my real life, or people's perceptions. It was tough, it wasn't sexy at all, it wasn't glamorous and I really loved that. Peter Berg, the director, his enthusiasm really played a big role in me signing onto this film. I felt safe, I felt I could trust him with it. He was just as enthusiastic about me playing the part," she explained.

"The blood running down my lip is so sexy," she quipped.