Actor Tim Roth said he fully supported assisted suicide, saying it was "crazy" that governments still opposed it, after playing an end-of-life nurse in his latest Cannes Film Festival entry on Friday.

"I'm all for it -- that's crazy to make people go through that," said Roth at a press conference after a screening of "Chronic" on the French Riviera.

Mexican director Michel Franco said he was surprised to find that many nurses helped people die regardless of the law.

"Tim and I were talking with all these nurses, and it turned out they do it more often than people realise," said Franco.

"I agree it should be legal and should be done in a proper way, but it also just happens all the time."

The film follows a nurse (Roth) in Los Angeles as he cares for several chronically-ill patients, dealing with families at a stressful moment and facing difficult moral questions about when to end a life.

"I wanted to make an objective portrayal of how complicated these moments of life are," said Franco, who began the project after watching his grandmother go through several months of care before dying.

"I was very moved and intrigued by the nurse who took care of her. I don't mean she's an angel," he said.

Roth chaired the jury that awarded Franco the Un Certain Regard prize for his film "After Lucia" at Cannes in 2012, and they have worked on two projects since.

"I saw his film and it devastated me, so I asked him for a job -- I mean, why wouldn't you?" said Roth. "And sometimes they deliver."
Source: AFP