A woman now living in Canada who witnessed the 1968 assassination of Sen. Robert Kennedy claims there was a second shooter besides Sirhan Sirhan.

In a weekend interview with CNN, Nina Rhodes-Hughes said she heard two guns fire as Kennedy walked through the kitchen pantry of the Ambassador Hotel after giving a speech in his bid to become the Democratic Party's presidential candidate.

The American-born Rhodes-Hughes, who now lives in Vancouver but was a TV actress and campaign volunteer at the time, claims police altered her account of the shooting, which took place only a few feet from her.

"What has to come out is that there was another shooter to my right," Rhodes-Hughes told CNN. "The truth has got to be told. No more cover-ups."

Rhodes-Hughes, now 78, said she's speaking out after years of frustration "to assist me in healing — although you're never 100 per cent healed from that. But more important to bring justice."

Sirhan, a Jordanian citizen who came to the United States in 1956, confessed he shot Kennedy because of his pro-Israeli views, Postmedia News reported. He later recanted his confession but is serving a life sentence in a California prison.

Last November, his lawyers filed documents in U.S. Federal Court suggesting that at the time of his prosecution, a bullet from the crime scene was switched to ensure it matched his gun to secure a conviction. Evidence presented to the court also includes a new audio analysis of a radio journalist's recording of the gunfire that one expert claimed points to 13 shots being fired.

The idea of a second shooter who actually fired the fatal bullets is crucial to reopening Sirhan's case.

Postmedia notes conspiracy theorists contend Sirhan was brainwashed into participating in a plot to kill Kennedy and used as a diversion to allow the real assassin to carry out the shooting and escape. Lawyers at the time never contested the prosecution's case that Sirhan was the lone gunman.

The 1963 assassination of Kennedy's brother, President John F. Kennedy, in Dallas has also been rife with conspiracy theories including claims of a second shooter.

Prosecutors in the current court challenge contend Rhodes-Hughes head no more than eight gunshots and "all these shots came from the same direction."

Sirhan's defence lawyer claims the FBI misrepresented her account that she heard 12 to 14 shots.

"She identified fifteen errors including the FBI alteration which quoted her as hearing only eight shots, which she explicitly denied was what she had told them," Sirhan's lawyers argued in February, citing a previously published statement from Rhodes-Hughes, CNN reported.

Other witnesses also claimed to have heard more than eight shots. Sirhan's gun could hold only eight rounds.

Rhodes-Hughes, whose stage name was Nina Roman, said Monday she met Kennedy in 1965 at a California TV studio where he was being interviewed and she was preparing for her role in a soap opera.

"We had a discussion about politics," she recalled. "He was very charming and very humble. And I told him 'If ever you decide to run for president, I would absolutely work for you.'"

After becoming involved in campaign fund-raising, Rhodes-Hughes said she was invited to come to the event at the Ambassador and help direct him to a conference room after his California primary victory speech.

Instead, she said, Kennedy was whisked in another direction to a shortcut through the kitchen.

"I started to shout, 'No, no, you're going the wrong way! You're going the wrong way!'" she recalled. "So I ran after him ... and suddenly I hear, Pop, pop, pop, pop, pop ..."