On a Monday afternoon last September, Michael Douglas is sitting on a couch in a suite at Soho House in Berlin’s Mitte district, talking about his father, the legendary actor Kirk Douglas, now 97. "He’s doing very well. I called him a few days ago, and the phone rang and rang. Eventually he picked it up, breathing heavily. I was worried and asked him, ‘Everything okay, Dad?’ – ‘Yeah,’ he answered, ‘I just finished my workout.’"

A while ago, Michael Douglas was asked a favor by his father, who had just completed his tenth book, I Am Spartacus, about the production of one of his most successful films. "Would you write the foreword?" Kirk Douglas asked, and his son was pleased. He had a lot to say about what it was like to grow up as the son of Spartacus – "not always easy" –, so he agreed to do it. "The next morning my dad sends me a message: Don’t worry about the foreword. You don’t have to write it. George Clooney just agreed to do it." And Michael Douglas laughs, in his deep, distinctive voice, which audiences have known for over four decades now. He is 69 years old, 1.78 meters tall, wearing a blue-gray suit, pink shirt unbuttoned at the collar, his hair swept back and parted down the middle. He is in Berlin for the German premiere of his film Behind the Candelabra , in which he plays the pianist Liberace. In the US, Władziu Valentino Liberace was one of the most famous entertainers of the twentieth century, having gained popularity through his music shows in Las Vegas and performances on TV. "It’s the first time I’m playing someone who actually existed," says Douglas. "It’s a new kind of responsibility for me, because so many people can remember him. In other countries Liberace is unknown. But in the US in the sixties and seventies, he was bigger than Elvis."

It took ten years before the movie about Liberace found any financing. "Maybe the studios thought that only gay people would be interested"

Michael Douglas actually encountered Liberace once, briefly. He was 14 years old, and his father was driving him through Palm Springs. "Suddenly a Rolls Royce convertible drove by with its top down. The first thing I noticed about the man in the Rolls was that not a hair on his head was moving. He wore a kind of kaftan and a whole lot of jewelry. The sun shone on his face, the jewelry sparkled. ‘Who’s that?’ I asked my dad. – ‘Oh, that’s Liberace.’"

From that day on, whenever Liberace happened to be on TV, Michael Douglas tuned in. "What we say in the film is actually true: He really was the first person to look straight into the camera. He invented that. That’s one reason why he’s etched into the memories of millions of Americans."

The pianist and singer Liberace kept his private life a secret up until his death in 1987, fearing that public knowledge of his homosexuality would damage his career. He even sued newspapers that tried to out him, testifying in court that he was not gay.

A fascinating biography, thought director Steven Soderbergh when he read the memoirs of Liberace’s longtime lover, Scott Thorson. So did the actors Matt Damon and Michael Douglas. And they came up with a plan: Douglas as Liberace, Damon as his lover, Soderbergh as director. What a lineup!

But it took ten years before the film found any financing. All the Hollywood studios passed on the project. "I don’t know the reasons for each individual rejection," says Douglas, "but I don’t believe that homophobia was behind it. Maybe the studios thought that only gay people would be interested in Behind the Candelabra . And as these days Hollywood is only interested numbers, that risk was simply too big for them."

Douglas, on the other hand, is somebody who loves to take risks. "Risks are sexy," he once said. "Of course it was risky to make this movie: two heterosexuals with our reputations making a movie about a gay couple. My gay friends were wary, ‘Better watch out that it doesn’t just turn into another version of La Cage aux Folles . I knew, though, that we could tell a great love story. That’s what I always banked on."

The film contains several sex scenes between Douglas and Damon. What was it like to shoot those scenes? "It wasn’t that different from being with a woman. You just try to make everyone feel as comfortable as possible." He pauses briefly and grins. "We only had one really intense sex scene. The camera’s running. Matt and I get going," says Douglas. "Bam-bam-bam! Bam-bam-bam! When we finish, Steven Soderbergh, who was also the cinematographer, puts the camera down and says: No further comment." Douglas gives another deep laugh.

Eventually, the television channel HBO took over the financing. It was rewarded with enthusiastic reviews and high ratings. The first broadcast of Behind the Candelabra became the most successful TV movie in almost ten years. At the Emmys last year, the film won a total of 11 awards, including Outstanding Lead Actor for Douglas (who famously offered to split the prize with his other leading man: "You want top or bottom?").

"You know what I noticed during production?" asks Michael Douglas. "Cancer has given me an advantage: I’ve become a better actor." In what way? "I have survived cancer. I have no fear." Two years ago, he announced that he was suffering from cancer of the larynx. He went through chemotheraphy and since then the cancer has not returned.