Guillaume died at Raymond-Poincare hospital in Garches, west of Paris, from complications related to a sudden case of pneumonia, the hospital's authority said.

He had been filming the movie "L'Enfance d'Icare" in Romania on the weekend when he suddenly fell ill.

The French actor, who is also famous for his tumultuous life, won the prize in 1996 as the most promising young actor at the Cesar awards -the French version of an Oscar - for his role in the film "Les Apprentis" (The Apprentices).

"He was very sensitive. That's what gave him that slightly James Dean-style personality. A man tortured by his youth, by the relations he had with his father," director Jean-Pierre Mocky, with whom he filmed in 1997, told RTL radio.

As a teenager and young adult, he led an eventful life and faced problems with drugs, alcohol and violence.

He served his first prison sentence at the age of 17 and returned to jail when he was 22 for heroin trafficking. He later said he had been a male prostitute as part of a revolt against his father.

He had a public falling-out with his father in 2003. That year he had his right leg amputated to end years of pain from a bacterial infection following a motorcycle accident in 1996.

Also in 2003, he was fined and handed a nine-month suspended prison sentence for threatening a man with a gun.

In June, he was jailed for two months for driving under the influence.