Hollywood star James Franco has lashed out at Australia for banning the US gay-themed film "I Want Your Love", calling the decision embarrassing.

Australia's Classification Board deemed the movie's sex scenes too explicit and refused to allow it to be screened at the upcoming Melbourne Queer Film Festival and the Brisbane Queer Film Festival.

Franco, best known for roles in the "SpiderMan" trilogy, blockbuster "Rise of the Planet of the Apes", and his Oscar nomination-winning turn in "127 Hours", said adults should be allowed to choose what they watch.

"I don't know why in this day and age something like this, a film that's using sex not for titillation but to talk about being human, is being banned," he said in a YouTube appeal to the Classification Board posted Monday.

"It's just embarrassing. I hope you'll reconsider."

The film, about a young gay man in San Francisco returning to his Midwestern roots, was directed by Travis Mathews, who collaborated with Franco on "Interior. Leather. Bar.", which premiered at the Sundance Festival in January.

Franco said Mathews was "using sex in such a sophisticated way".

"It's how we create children, it's how we connect," he said.

"To keep it away from films that want to explore it as human behaviour is very shortsighted and I think very hypocritical. I don't think we would be having this conversation if he had made a very violent film."

The Melbourne Queer Film Festival runs from March 14-24, and the Brisbane edition is held from April 5-14.