In defending his decision to play a gay role in his directorial film debut, actor Viggo Mortensen suggests he might not be “completely straight.”

In the Falling, Mortensen, who is best known for his roles in the Lord of the Rings trilogy and Green Book, plays a man whose father is suffering from dementia. The racist and homophobic father comes to live with his son and husband, who is Chinese-Hawaiian, in Los Angeles.

The movie premiered earlier this month in Britain.

Activists have criticized straight, cisgender actors who play LGBT characters. Halle Berry recently pulled out of a transgender film role over backlash that a transgender person should be offered the role.

Speaking with UK LGBT glossy Attitude, Mortensen, who also wrote and directed the film, defended his casting decisions.

"And how do you know what my life is? You’re assuming that I’m completely straight. Maybe I am, maybe I’m not. And it’s frankly none of your business,” Mortensen, 62, said.

"I want my movie to work, and I want the character of John to be effective. So if I didn’t think it was a good idea I wouldn’t do it,” he said.

In a separate interview with The Times, he called the debate “healthy.”

“Look, these are the times we’re living in, and I think it’s healthy that those issues are brought up,” Mortensen said. “The short answer is that I didn’t think it was a problem. And people then ask me, ‘Well what about Terry Chen, who plays my husband in the film, is he a homosexual?’ And the answer is I don’t know, and I would never have the temerity to ask someone if they were, during the casting process."

(Related: Supernova stars Colin Firth, Stanley Tucci on straight actors playing gay.)