A Christian singer gave permission for one of his songs to be used in the 50 Shades of Grey film because he believed it was a romantic comedy.

Paul Janeway, lead of singer of soul band St Paul and the Broken Bones, based in Birmingham, Alabama, told the website Mother Jones he hadn't heard of the film, based on EL James' erotic BDSM novel.

He said: "When they presented the licensing opportunity, they presented it as: It's going to be a huge movie, they want to put a decent amount of the song in the movie in a nonsexual scene.

"I knew it was a book, but I had no idea what it was. So I was like, sure, big movie, good exposure. I'll be in this romantic comedy. Which is what I thought it was: a romantic comedy. It's a good way to make money in the music business, you know. Then I saw a preview for it, and I was like, '...Oh, no. What have I done?'

Janeway, who grew up in a strict religious household, wanted to be a preacher until he was 18 and learned to sing at his Pentecostal-leaning church.

His current music has its roots in church, and religion is still part of Janeway's life - but he says the relationship remains complicated.