Bradley Cooper shared a laugh with Prince William at the British Academy Film Awards.

The 'A Star Is Born' director and actor met the Duke of Cambridge - who is the president of BAFTA - at the ceremony and they shared a joke about Bradley's hidden singing talent.

William told the actor: ''Congratulations, great film. I didn't know you could sing!''

To which Bradley quipped back: ''I didn't either.''

And when Prince William asked if Bradley ''always'' had Lady GaGa in his mind to play opposite him in the movie, he admitted: ''Not originally. But then it was dormant for a while, and I saw her perform and that was it.''

And William replied: ''That's a really amazing story.''

Bradley loved the challenge of balancing acting and directing.

He explained: ''I've never been more fulfilled and have it feel more natural. I love acting, and I love acting and directing.''

The movie also saw Gaga star in her first major movie role as a nightclub singer-songwriter and Bradley admitted they both took a significant risk with the project, and that their personal relationship was key to the film's success.

He added: ''Clearly, we were both entering into worlds we didn't know, and each person had been very comfortable in their world for at least a decade - or two, in my case. I hope that gave her comfort in the way she gave me comfort ...

''I knew right away we were going to tell each other the truth; there's no reason not to because eventually everybody's going to say what they really think. I was convincing her it was working and she was the same about me, so we provided a great barometer [for each other].''