THE son of Jean Seberg, the American actress and icon of France’s “new wave” cinema, has accused the FBI of fuelling the psychological pressure that drove her to commit suicide with an overdose of drugs and drink three decades ago.

“My mother felt persecuted,” said Diego Gary, referring to a “destabilisation campaign” against Seberg by the FBI on account of her support for the Black Panthers, a far-left group dedicated to promoting “black power” in America.

“There were moments when she was very afraid,” he said in an interview last week. “She hired two bodyguards to protect her because she had received so many threats.”

Seberg is best remembered as the elfin American called Patricia who befriends a gang-ster played by Jean-Paul Belmondo in Jean-Luc Godard’s 1959 film Breathless, a key work of the new wave in French cinema.

Subsequently Seberg attracted the attention of J Edgar Hoover, the FBI director, through her political activism. There were suspicions of foul play when her naked body was found wrapped in a blanket in the back of her Renault not far from her Paris flat in September 1979.

However, Gary, son of Seberg and Romain Gary, a revered French novelist, does not believe she was murdered. She apparently took a massive overdose of barbiturates and the quantity of alcohol in her blood alone might have been fatal. She had previously made several attempts at suicide.

“She left me a note that was definitely in her handwriting,” said Gary, whose book about the tragic family story – his father also killed himself – appeared recently under the title S. or Hope of Life. “She said that she could no longer live with her nerves. ”

In the years following her death it emerged that the FBI had Seberg under surveillance and her telephone was tapped. The actress knew that she was being watched but her friends at the time thought she was “paranoid”, Gary recalled.

Seberg was devastated when an American columnist published an item, planted by the FBI, claiming that she was pregnant from an affair with a Black Panther. She delivered the child prematurely and the baby died four days later. She ordered a “glass coffin”, said Gary, so that people could see the child was white.

Gary says that as a child he resented the way that Ahmed Kemal, one of the Panthers, monopolised his mother’s attention. One day, aged seven, at lunch with Seberg, he hit Kemal over the head with a candelabra. “He came towards me with his fists raised,” Gary recalls. “He was shouting at me, ‘I’m gonna kill this little bastard!’”

Gary took refuge in the next room and Seberg had to intervene to stop Kemal hitting him: “He’s just a kid, don’t hurt him, don’t hurt him please!” he remembers her screaming.

He believes that his mother, from Iowa, was manipulated by the Panthers, who extracted large sums of money from her.

“She allowed them to play on her guilt about being a white, Lutheran cinema star from the impoverished Midwest.” He described the Panthers as being “more thugs and pimps than apostles of freedom and equality for people of colour”.

As a child Gary spent more time with Eugenia, the nanny whom he called “Maman”, than either of his parents. “You have little time for a child when you are a star travelling from one set to the next around the world,” he says.

He will never forget how his father, winner of the Goncourt literary prize, announced at a press conference that he was divorcing Seberg, citing her affair with Clint Eastwood, Seberg’s co-star in the musical Paint Your Wagon.

The young Gary became his parents’ go-between. Staying in her apartment was a traumatic experience for the teenager. “Sometimes, she would sit there talking to the refrigerator,” says Gary, recalling his mother’s slide into insanity. He remembers her bursting into his room at 5am one day to ask whether she could borrow a pair of his shoes.

Another time she woke him up when drunk to introduce him to a woman friend. “You see, I’m being picked up by lesbians now, what do you think?”

A year after Seberg’s death, Gary’s father shot himself in the head, leaving a note saying only, “Nothing to do with Jean”. Gary inherited money, hired a butler and studied literature. He worked for a while asa television producer. The family’s painful legacy was too much for him, though, and he drowned his sorrows in drink.

He toured the brothels of Europe and said, at the age of 47, that he had finally found happiness in the arms of a Lithuanian hostess he met in Barcelona. They married and are expecting a daughter.

Times Recommends

• No apology for Germany’s own Nazi victims
• Intricate web of fear and hope tying down deal
• Victims remembered a year after Mumbai attacks