Wellington  - A New Zealander who served more than 12 years in prison for the murder of his parents and three siblings, and who was released on bail after a campaign declaring him innocent, went on trial again Friday on the same charges.

David Bain, 36, was freed in 2007 after the Privy Council in London - then New Zealand's highest court - ruled he had been the victim of "a substantial miscarriage of justice" when he was first tried in 1995 and sentenced to a minimum of 16 years in jail.

The council said the jury might have reached a different verdict had it heard the nine points of evidence raised by Bain's lawyers at his appeal in 2007.

The Privy Council did not declare him innocent and although the solicitor-general could have abandoned the case he decided that Bain should face another trial.

A new jury of seven women and five men was sworn in at the Christchurch High Court for the retrial, which is expected to take three months with the prosecution calling 150 witnesses.

Bain again pleaded not guilty to shooting to death his father, Robin, 58, mother Margaret, 50, sisters Arawa, 19 and Laniet, 18, and brother Stephen, 14, at the family home in Dunedin on June 20, 1994.

Bain's defence throughout has been that he was out on his morning newspaper delivery round when his father, who was having an incestuous affair with Laniet, killed the other family members before turning the gun on himself.

A high profile campaign to prove Bain's innocence was spearheaded by Joe Karam, a businessman and well-known former national rugby star who wrote a book on the case called "David and Goliath."

He said it began when he read a newspaper article in 1996 with a photo of Bain's singing teacher and some of his university and opera society friends who were selling jam to raise funds for an appeal.

"I rang with a view to giving them a couple of hundred dollars and that's how I got involved," he said 11 years later.

Karam said he believed "without a shadow of doubt" that Bain was innocent.

New Zealand's most well-known victim of injustice, Arthur Allan Thomas, who served nine years in prison for a double murder in 1970 he was later ruled not to have committed, was at the court to support Bain. He told reporters he was there to see justice done. (dpa)