By Ian Gunn BBC correspondent in Vancouver

Ripudaman Singh Malik is on trial along with Ajaib Singh Bagri

Two Canadian men are on trial for a pair of bombings in 1985 that killed more than 330 people.

One bomb exploded on an Air India jumbo jet over the north Atlantic killing everyone on board.

Now a new witness at the murder trial says months before that crash one of the accused sought help with the bomb plot.

The witness cannot be named because the judge has ordered that his identity be kept a secret.

But late last year, with this trial already well under way, he approached prosecutors with a story that directly implicates Ripudaman Singh Malik, one of the two men accused of the bombings.

Revenge

In his testimony, the witness alleged that Mr Malik took him aside one day at the local Sikh temple and asked him to drop a briefcase off at the Vancouver airport.

He was told the case contained a time bomb and that it would destroy the plane that it was on.

The witness says he refused because of the number of innocent people it would kill.

He says he believed the attack was to be Sikh revenge for the storming of the Golden Temple at Amritsar by Indian troops a year earlier.

The witness did admit that he is in serious financial trouble, but denied suggestions he has suddenly come forward in the hope of collecting a reward.

Another witness at this trial was recently paid $300,000 for his testimony.