The High Court trial for two people accused of murdering Christchurch woman Angela Blackmoore almost 30 years ago has been aborted.

It comes after new material came to hand that lawyers need time to review.

The 21-year-old was bludgeoned and stabbed 39 times in her Wainoni home while her two-year-old son slept in 1995, in what Crown prosecutors argued was a brutal "contract killing".

David Hawken, 50, and Rebecca Wright-Meldrum, 51, are accused of plotting her murder with a third person - Jeremy Powell - who pleaded guilty to the young mother's murder in 2020 and is serving a minimum of 10 years in prison.

The jury trial began on 1 May and was scheduled to last four weeks but this afternoon Justice Cameron Mander told the court it must be abandoned.

"This morning I made the decision after having heard from counsel to abort this trial," he said.

"I can't go into the details with you as to why that has arisen, except to broadly indicate to you that material has come to hand which counsel need the opportunity to review."

Justice Mander said a series of adjournments were taken in an endeavour to manage the situation and ensure counsel were prepared and could continue with the trial.

"Despite best endeavours to continue with the trial, those efforts have effectively been in vain," he said.

"I have made the decision that we have reached the point that the only proper course in the interests of justice is for this trial to be abandoned."

Justice Mander said the decision would be a source of frustration for jurors and thanked them for their service before they were formally discharged.

A new trial date is expected to be set at a hearing on 26 May.

Hawken and Wright-Meldrum have denied any involvement in Blackmoore's death.

The court earlier heard Hawken ordered Powell to kill Blackmoore with the help of Wright-Meldrum, offering $10,000 to carry out the hit in order to gain control of matrimonial property interests.

Wright-Meldrum and Blackmoore had been close friends since the early 1990s and at one point, lovers.

Wright-Meldrum is accused of using her friendship with the security-conscious Blackmoore to get Powell into her house, along with helping to clean up after the attack and dispose of the weapons.

Wright-Meldrum's defence lawyer Stephanie Grieve KC said the jury would need to decide whether Powell was a "credible and reliable" witness when he said she was there when he murdered Blackmoore.

Hawken's defence lawyer Anne Stevens KC told the jury Powell was a murderer and a liar and had implicated her client to minimise his own culpability.

Hawken had no power and no money to order a murder, she said.

Photo: Supplied / NZ Police