"I don t make public films, I make private films," Carax told a press conference in English. "I ll let whoever wants come and see it."

Dubbed both "heartbreaking" and "completely bonkers" by reviewers at the Riviera festival, Carax s experimental parable on life s futility, co-starring Kylie Minogue and Eva Mendes, has shot to the front of the Cannes race.

Starring French actor Denis Lavant in no fewer than 11 roles, the visually powerful film tells of a man who slips actor-like between shifting identities, in a succession of tableaux alternately wacky, serious and moving.

It notably features a flame-haired troll carting off a fashion model played by Mendes to his underground den, a duo in motion-capture suits miming a sex scene, and an intermission by a band of jamming accordionists.

Asked for the meaning of the troll sequence -- which sees the grunting, goateed imp clothe Mendes in a makeshift burqa before lying, aroused and naked, on her lap -- Carax replied: "How would I know?"

In the notes to the film, Carax said the troll -- dubbed "Mr Merde" (Mr Shit) -- was an archetype intended to embody "fear and phobia" and a regressive spirit that he saw taking root after the September 11 attacks in 2001.

Questioned again about his relationship with the audience, the shade-wearing director said: "I care about being seen. As to being understood, well. Loved? Yes, if there is one person who loves me I will be happy."

"Exhilarating, opaque, heartbreaking and completely bonkers," was how the Hollywood Reporter summed up Carax s movie.

"It s brave and foolish," wrote the magazine, saying the film "immediately bolts to the front of the pack in the race for the Palme d Or and into an elated tempest of debate and speculation."