(Cover) - EN Movies - Selena Gomez turned to old videos of Britain's late Princess Diana to perfect an English accent for her new film.

The 18-year-old stars in Monte Carlo, which features Selena as a down on her luck US student who discovers she is the spitting image of a rich and spoilt British heiress. With the help of her two friends, played by Leighton Meester and Katie Cassidy, she takes on the guise of the socialite while holidaying in Monte Carlo.

The role required Selena, girlfriend of teen pop sensation Justin Bieber, to display a convincing English accent.

"I looked up interviews of Princess Diana," she told the British edition of OK! magazine. "If you ask any American to do a British accent, they always go, Cheerio!' They go really high and that's what they do to get a guy's attention."

But it wasn't just the English accent she had to perfect for the movie. While shooting the film in Budapest, which stood in for Monte Carlo, she had to learn how to play polo, which is a sporting favourite of the British royal family.

"I loved it! I did the polo training there I was very bad!" she laughed. (C) Cover Media