TOKYO: Japanese director Koji Wakamatsu, who ruthlessly challenged authority with the grotesque and sexual, has died after a traffic accident this month. He was 76.

His production company said on its official Twitter site Thursday that Wakamatsu died late Wednesday after being hospitalized unconscious from being hit by a car. "We thank you all for your kindness over his life," it said, adding other details will be announced later.

Wakamatsu's "Caterpillar" depicts a soldier during imperialist Japan's pillaging of neighboring China, who returns scarred, and with no arms and legs but with an ample sexual appetite. Shinobu Terajima, who played the soldier's enduring wife, won the Silver Bear award for Best Actress at the 2010 Berlin Film Festival.

Wakamatsu ventured into pornography, especially early in his career, but his artistry managed to turn such works into a pensive critique of society. While he was never afraid to offend the faint-hearted, his in-your-face realism won fans among the more adventurous.

His works tended to pick stories from real life. His film about the United Red Army, a Japanese left-wing terrorist group of the 1970s, that tortured its own members, won the Art Cinéma Award at the 2008 Berlin Film Festival.

He turned his attention to right-wing extremism with his latest film, "The Day Mishima Chose His Own Fate," premiering at Cannes earlier this year. The work focuses on writer Yukio Mishima, who took over the Japanese defense offices, making speeches bemoaning a weakened subservient Japan, and then disemboweled himself in ritualistic "hara-kiri" in 1970.

"The Millennial Rapture," shown at this year's Venice Film Festival, also starring Terajima, was based on a novel by Kenji Nakagami, a Japanese writer of "buraku" ancestry, an underclass from feudal times that remains unfairly discriminated today. In the film, dapper but unruly men seduce one woman after the other.

Terajima said she felt a deep loss.

"Always so kind, always siding with the victims, always lashing out at the powerful, my director," Terajima said on her blog. "You always loved good sake and good food. And what you loved most passionately was making movies."

Wakamatsu was honored as Asian Filmmaker of the Year at this year's Busan Film Festival.

He had just returned from South Korea, when he was hit by a cab and seriously injured in Tokyo last week, according to the Yomiuri newspaper.

Wakamatsu acknowledged recently his vision had changed with age.

"Once I got to 50, I decided I wanted to make films that people can look back at in 50 or 100 years and think, 'That's what it was like in those times,' " he told the Hollywood Reporter in Busan. "That's the kind of films I'm trying to make."