When the trailer for Southpaw dropped a couple of days ago, everyone got excited about the new Eminem song used on it and about Jake Gyllenhaal looking all pumped up and beefy.

However there was another little treat squirreled away in the two-and-a-half-minute promo - a blink-and-you'll-miss-it shot of Rita Ora playing a junkie.

[related]The 24-year-old pop star and The Voice coach is seen peeking nervously around a door as Gyllenhaal's troubled boxer arrives - and she has admitted that she needed some acting help from the movie hunk.

She told Germany's Glamour magazine: "It was an incredible experience. Jake made it very easy for me.

"The role that I play is indeed very far away from my real life but this role made me see a few things differently now.

"To be honest I needed a lot of coaching and some speech training, because I had to have a certain accent.

"It was really great to go into a completely different world but it was not always easy."

Directed by Training Day filmmaker Antoine Fuqua, the new movie sees a down-on-his-luck boxer fighting to rebuild his family.

It was originally intended as a vehicle for Eminem, but the lead role eventually went to Gyllenhaal - who had to bulk up big-style after his gaunt appearance in Nightcrawler.