Rita Ora was careful not to ''embarrass anybody'' filming 'Fifty Shades of Grey'.

The 23-year-old singer is set to try her hand at acting in the new blockbuster adaptation of E.L. James' best-selling erotic novel and she admits she was so nervous about her role - playing Christian Grey's sister Mia - she worried she would mess up.

Appearing on Capital FM's Vodafone Big Top 40 on Sunday night (11.05.14), she said: ''I've just shot the movie, 'Fifty Shades of Grey'. That took up a lot of my time as I didn't wanna embarrass anybody, so I made sure I knew exactly what I was doing.

''It was an incredible experience. I went from not knowing what it's like being on a movie set, to feeling like I knew them all for years, and I wasn't even there for that long.''

'Fifty Shades of Grey' will star Irish hunk Jamie Dornan in the role of bondage-loving Christian Grey and newcomer Dakota Johnson as his virginal paramour Anastasia Steele.

Ora admits part of her nervousness stems from joining the film's cast so late into production.

The singer explained: ''They'd already been filming for months and months, so I came in mid-way through the film. I can honestly say it's so cool to be in it. I'm so excited, I was really nervous. I kind of came in last minute, I auditioned last minute.''

'Fifty Shades of Grey' is out next Valentine's Day (14.02.15).

Catch The Vodafone Big Top 40 every Sunday at 6pm with Capital presenter Marvin Humes .