British singer Rita Ora poses for photographs at the British Fashion Awards in London CREDIT: REUTERS

Rita Ora is officially joining the cast of the upcoming movie adaptation of Fifty Shades of Grey.

The British singer announced through her Twitter account that she has been cast in the movie as Mia.

'It's official! I've been cast in @FiftyShades of Grey as Christian's sister Mia. #FiftyShades,' writes the "How We Do" singer.

The Daily Mail, however, wonders how her best friend Cara Delevigne will react with the news. It was reported that the Victoria's Secret model auditioned for a part in the movie but failed to do so.

Rita joins Jamie Dornan and Dakota Johnson in the cast of characters in the movie, which also includes Luke Grimes, Jennifer Ehle, Victor Rasuk, Eloise Mumford and Max Martini.

This is not the first time Rita ventured into acting. The singer had acting training while studying at the Sylvia Young Theatre School. In 2004, Rita appeared in the British movie "Spivs" and last year, she played a racer in the sixth installment of "The Fast and The Furious" franchise.

Rita was best known for her recording career, releasing her debut album Ora in 2012 and includes her hit single "How We Do (Party)."

"Fifty Shades of Grey" is based on a novel series of the same title written by E.L. James, which follows the extraordinary affair between Christian Grey (Jamie Dornan) and college student Anastasia Steele (Dakota Johnson). In the said novel, Mia is one of Carrick Grey and Grace Treveylan's adopted children, including Christian and Elliot (Luke Grimes).

Last week, Jamie and Dakota were spotted at a coffee shop in Vancouver in the first day of filming of the movie. It appears that the two are filming the coffee date scene where Christian gets to know Anastasia after they first met in an interview.

The movie directed by Sam Taylor-Wood is set for release on Feb. 13, 2015 after the production team incurred delays primarily due to the pullout of Charlie Hunnam from the cast. The actor is set to play Christian Grey until he pulled out due to scheduling and personal reasons, and was eventually replaced by Jamie Dornan.