LOS ANGELES (AFP) - US Senator Edward Kennedy went to his death in 2009 haunted by his role in the drowning of a young woman 40 years earlier after he crashed their car.

The accident at a bridge on Chappaquiddick Island stained his reputation and destroyed his chances of entering the White House.

"It was the event that changed the course of Teddy Kennedy's career," said John Curran, director of Chappaquiddick, a new movie delving into the mysterious events surrounding a tragedy that has enthralled America for half a century.

Speaking at the premiere in Beverly Hills ahead of the movie's US release on Friday, Curran described himself as a fan of Mr Kennedy.

"I do realise I've had this sort of blind spot about this episode in his life and it just felt time to re-examine it honestly," said the 57-year-old film-maker.

Mr Kennedy boasted a rich family political legacy linked to an era of civil rights gains as brother of President John F. Kennedy and Attorney General Robert F. Kennedy.

The Massachusetts senator's own legislative achievements since his election in 1962 at age 30 helped craft his legacy as one of the most accomplished lawmakers in US history.

In True Compass, his memoir published weeks after his death in 2009, he stuck to his assertion that Mary Jo Kopechne's death on July 18, 1969 was an accident.

Critics have long speculated that the last of the four Kennedy brothers was drink-driving and left the dead or dying 28-year-old campaign worker behind to cover his tracks and save his fledgling career.

Mr Kennedy, who had offered her a ride home from a party, swam to safety after the crash but left her trapped in his Oldsmobile, lying on its roof in shallow water.

In his memoir, he admitted it was "inexcusable" that he did not report the accident to police until her body was recovered the following day but denied driving under the influence of alcohol, or any affair.

The film stars Jason Clarke and Kate Mara.