French rock star Bertrand Cantat has told the first day of his murder trial that the death of his girlfriend Marie Trintignant was a tragic accident.

Cantat, the frontman of Noir Desir (Black Desire) is accused of murdering Trintignant, one of France's most famous actresses, during a row in a hotel room in Lithuania.

Both Cantat and Trintignant are huge stars in France and the trial is receiving saturation coverage in the French media. The case has gripped and horrified the country where the love affair between the two artists has been the focus of public fascination.

Cantat admitted slapping his 41-year-old girlfriend in a drunken rage on July 28 last year, but said that he never meant to kill her.

The multi-millionaire singer, held in the Czarist-era Lukiskes Prison in Vilnius since his arrest eight months ago, told judges that he hit the film star four times in a drunken stupor - contradicting prosecutors who said that he fatally punched her at least 19 times in a jealous rage.

"Everything happened very fast," the singer told the court today. "Never, never did I want things to happen that way. This hand should never have risen. And I do not accept myself having raised this hand."

He also said that the couple loved each other very much despite their often tempestuous row.

An ambulance was called to the hotel at around 7.30am by which time Trintignant had already been in a coma for two hours.

While still in a coma and on life support, she was flown by private jet days later to France dying the next day, August 1.

"We loved each other and our love was growing," the 40-year-old Cantat told a three-judge panel in testimony lasting over an hour at the District Court in Vilnius, the Linthuanian capital.

He faces a maximum 15-year jail sentence, with the judges expected to hand down a verdict and sentence this week.

Over 50 reporters and photographers, mostly French, packed into the breezy, white-pillared courtroom to cover the trial.

Family and friends of both Cantat and Trintignant attended, with the actress's mother, Nadine Trintignant, arriving dressed entirely in black. Cantat's parents, as well as members of his band, sat nearby.

Cantat was clean shaven and seemingly calm in stark contrast to his appearance last year at a pretrial hearing where he looked dishevelled and dejected.

While some rallied to the left-wing singer's defence, he is reviled by others. His house in France was recently destroyed by fire in mysterious circumstances, with many believing it was a revenge attack for Trintignant's death.

The daughter of actor Jean-Louis Trintignant was in Lithuania completing a film called Colette, about an early feminist. Her mother directed the film. The actress was celebrated for often playing brutalized women in over 30 French and several English-language films.

Her death has since prompted public soul searching about violence against women.

Her funeral was at the Pere Lachaise Cemetery in Paris, where writer Oscar Wilde and rock star Jim Morrison are also buried.