Celine Dion reveals shocking fact about Titanic movie

Leonardo DiCaprio and Kate Winslett in the movie Titanic. Photo / Supplied

Celine Dion drew audible gasps from a talk show audience when she revealed that she almost refused to record her hit My Heart Will Go On for the film Titanic.

The song went on to become one of her biggest hits and one that defined her career and made her even more of a household name, but at he time she says it "didn't appeal".

Speaking to Andy Cohen on Watch What Happens Live this week, Dion told a stunned crowd: "There was one song that I didn't want to record, and I'm glad they didn't listen to me."

After the audience gasped, she dramatically confirmed: "It is true. It didn't appeal to me. I was probably very tired that day — very tired."

It was her late husband Rene Angelil who we can all thank for twisting her arm.

"My husband said, 'Let's hold on' to the writer and he said, 'Let's try to make it, like, a little demo.'"

Reluctantly, she agreed to sing the song as a demo but because of that reluctance, composer James Horner and writer Will Jennings made do and wound up creating the film's score around the demo.

"I sang the song once and they built the orchestra around it. I never re-sang it for the recording. So the demo is the actual recording," she admitted.

Joke's on her though because she then added: "But after that, I've sang it about three gazillion times."

According to People, the song debuted at No. 1 on the Billboard chart in 1998 and held the film's soundtrack at No. 1 for a massive 16-week run.

It also took home the Oscar for best original score and won record of the year at the Grammys.