The relationship between the flamboyant pianist Liberace and his young lover dazzled at the Cannes film festival on Tuesday and threw the spotlight on gay rights at the movie industry's largest annual gathering.

Director Steven Soderbergh said he struggled five years ago to secure funding for Behind the Candelabra because some financiers thought the film would only appeal to gay audiences and, at a cost of $25 million, would be a financial risk.

Eventually he received financing from Time Warner's HBO cable channel and made the film with Michael Douglas playing Liberace and Matt Damon as Scott Thorson with whom the pianist had a secret five-year affair.

Soderbergh said it was a coincidence that the film was being released during a global debate on gay rights and same sex marriage but acknowledged that it was very timely.

France last month became the 14th country to legalize gay marriage, a move also taken in the US by Washington D.C. and 12 states. Liberace, a huge celebrity during his lifetime, publicly denied his homosexuality at a time when being gay was considered taboo.

"In making the film, the sociopolitical aspect of it was not really in my mind but I was focused on... trying to make this relationship as believable and realistic as we could," Soderbergh told a news conference, flanked by Douglas and Damon.

"When this issue comes up, of equal rights for gays, I am hoping 50 years from now we will look back on this and wonder why this was even a debate and why it took so long."

Douglas and Damon said they were both keen to work with Soderbergh who has said he will retire from filmmaking after this movie.