An appeals court has upheld a ruling that the makers of controversial movie Natural Born Killers cannot be prosecuted for a young couple's violent crime spree, according to its film studio.

The Louisiana Court of Appeal has upheld a lower court's earlier dismissal of a lawsuit against director Oliver Stone, Warner Bros said.

The lawsuit claimed the film prompted the couple to shoot and paralyse a shop assistant in 1995.

Woody Harrelson played a crazed murderer

Another person was shot dead by Sarah Edmondson and her boyfriend Ben Darras - who said they had watched the film over and over again - during their rampage.

The appeals court said film-makers had the right to free speech under the First Amendment, and that nothing in the film advocated or incited viewers to commit violence, according to Warner Bros.

The 1994 movie starred Woody Harrelson and Juliette Lewis as two young lovers who commit numerous robberies and murders during a wild spree. It hit the headlines for its graphic depiction of violence.

The lawsuit was brought by the family of Louisiana store clerk Patsy Byers, who was left a quadriplegic after the robbery attempt by Edmondson and Darras.

Edmondson, who was seen on a surveillance video firing a bullet into the clerk's neck, is serving a 35-year prison sentence for the crime.

Darras is serving a life sentence for the killing of a Mississippi man during the same crime spree.

Ms Byers died of cancer two years after the attack.

'Hopeless'

Warner Bros said they were "gratified" by the ruling, and that any decision against them would "pose a grave danger" to freedom of expression.

Oliver Stone's lawyers have said that the film did not cause Miss Byers to be shot.

Miss Byers' family have not decided whether to pursue the case further, attorney Joe Simpson said.

"I have to consult with the other attorneys. My vote now would be to stop. In my opinion, it's hopeless to go any further," he said.