LOS ANGELES, July 13 — Eminem and Gwen Stefani have released a song together for the soundtrack of the boxing drama “Southpaw”.

"Kings Never Die" follows Eminem's "Phenomenal," which also appears on the film's soundtrack and was released in June.

Stefani told Entertainment Weekly that she’s always wanted to work with the rapper, but that her voice almost failed her.

The No Doubt singer said, “I’ve always wanted to work with him — he’s a genius — and then all of a sudden they called me and said, ‘It has to be done today’ and I was like, ‘Ah, my voice’ — I had a cough or something. I went in and I made it happen, but it was like, barely.”

“It was like, ‘God, why does today have to be the day my voice is not happening?’ But it ended up turning out good. I wanted to do something with him for so long and I feel honored — he’s very selective. I feel really honored.”

The 42-year-old rapper was supposed to star in “Southpaw”, a role which now filled by Jake Gyllenhaal.

Gyllenhaal plays a professional boxer who struggles to put his life back together and regain custody of his daughter after the death of his wife, played by Rachel McAdams. 50 Cent, Rita Ora and Forest Whitaker also star.

The film is slated for release in US cinemas on July 24.