Convicted murderer Isaiah Natana has taken his case to the Court of Appeal on the basis that police did not disclose a potential alibi to trial lawyers.

Natana was found guilty two years ago of murdering Meihana Mason in his Tāneatua home.

He was jailed for life with a minimum non-parole period of 12 years.

Crown prosecutors alleged that Natana and associates went to the victim’s house on February 14, 2022, in search of drugs to buy.

When they were declined, the encounter turned violent, resulting in Mr Mason being beaten so severely that he died in hospital the following day.

Natana and two co-defendants went to trial in October 2023, denying the roles they were accused of playing during the fatal incident and two following assaults.

Now, a witness has sworn to Appeal Court judges that Natana was with her while the assault was under way, and police knew about her statement while the trial was ongoing.

The appeal was heard by Justice Neil Campbell, Justice Rebecca Edwards and Justice Jonathan Eaton in Auckland last week.

Natana testified in court for the first time about his account of the day, with the support of a communication assistant, after opting not to take the stand during his trial.

The patched Mongrel Mob member admitted that he initially lied to police by saying he was home with his family.

Natana said he had been drinking with some associates earlier in the day and they went to buy drugs from Mr Mason.

He was told “no”, relayed the message to his associates in the car, and they drove around the block before returning to the address.

Natana said that while the others went inside, he went to visit someone else he knew in the area. That person has been granted name suppression and was referred to in open court only as “Witness X.”

They were drinking cups of tea when they heard banging and yelling, which prompted Natana to investigate what was happening at Mr Mason’s place.

“When I walked towards the cabin, I heard some banging. I walked in and he was beating up Koro Mei.”

Natana told Crown solicitor Robin McCoubrey he stopped the fight, but the victim had already sustained a beating.

He thought that was when he ended up with Mr Mason’s blood on his shoes, which became a key piece of prosecution evidence at trial.

“I didn’t want to be a part of it, so I went back to tell [Witness X] what was going on.”

Notes from Natana’s trial lawyer were entered into evidence at the appeal hearing that referred to a conversation about whether Witness X should be called to testify about him having a feed at her house.

Reading from the notes, Mr McCoubrey said Natana “could not remember if he even had a feed there that day, and he did not know if she would accept it.”

Natana then opted not to have Witness X called to give evidence in person, and her written police statement was submitted as evidence instead.

Under cross examination, Natana said he was offered a feed, but he only had a cup of tea.

Mr McCoubrey put to Natana that there were inconsistencies in the stories he told prior to the murder trial compared to Appeal Court, specifically his return to Witness X’s house.

Natana said he “might have missed that out.”

He said he was not sure if he’d told his lawyer everything he went on to share in the Court of Appeal.

Despite the trial prosecutor claiming he’d committed murder, he could not take the stand then because of threats made against him and his family.

Natana said he had to tell his version now.

“I have to do this. I’m going to go down for a murder I didn’t do.”

Mr McCoubrey said the criminal trial was the point when Natana might go down for murder.

Witness X took the stand following Natana’s testimony and said he visited her once on the day Mr Mason was fatally assaulted.

She was cross examined by the Crown solicitor about the witness statement she gave police within a week of the victim’s death, and the affidavit she signed for the Appeal Court.

Of the original statement, Witness X said she included only what happened inside her house. Mr McCoubrey said she referred to a relative being in the house with her but made no mention of Natana’s visit.

She told the Appeal Court that Natana visited her once that day, but she had no reason to believe he was with the group who assaulted Mr Mason, so she did not tell police he was with her.

“He came alone, so I’m not going to stick him with those fellas, if you know what I mean.”

She did not think she should have to tell police who was in her house. Mr McCoubrey asked how police were meant to know what happened if witnesses did not tell them everything they knew.

“I don’t know what happened, so I can’t tell police what happened,” Witness X said.

She said that although people in town had been talking about Mr Mason’s death, she did not know Natana was on trial for murder until she read about it in a newspaper report that mentioned he had a drop of blood on his shoes.

The affidavit she signed for the Court of Appeal stated that he specifically did not have blood on his shoes.

Further into the cross examination, the witness said she did not see his shoes because she looked him in the eye while talking to him. She maintained that she did not see blood on him, at all.

Mr McCoubrey said none of those details had been included in the witness’ statement seven days after the assault.

The Crown solicitor raised that Witness X was in frequent contact with police and had the opportunity to amend her statement before that point.

A police detective attempted to get Witness X to attend the trial in Hamilton, but she said she could not make the trip due to other responsibilities. “They have my statement. There is nothing more they can say,” was the text she sent back to the detective, Mr McCoubrey said.

Witness X said her relationship with the police, and the specific detective she was in contact with, was strained.

She texted Natana’s parents about his visit with her before telling police, she said.

The police detective contacted by Witness X gave evidence, confirming he received a text message from her on October 28, 2023 – the first Saturday after the trial started.

He said the text came among a series of other messages from the witness.

They arranged to meet the following day to get an updated statement, given her message was inconsistent with her initial statement and her comment a few days prior that she had nothing else to say.

The interview did not occur.

The detective told the officer in charge of the file about the texts but did not disclose them to the Crown prosecutor or Natana’s defence lawyer.

Defence lawyer Philip Hamlin suggested there should have been some urgency by police to speak to Witness X, given the trial was due to conclude the following week.

The detective said another outstanding witness was the priority, and Witness X’s writing style made it difficult for him to understand what she wanted to say.

He said the pressures of the trial meant no further action was taken when the interview did not happen, and there were no alarm bells to him that it was urgent, because of the witness’ earlier messages.

The detective said he had not deliberately withheld the messages from the defence and Crown lawyers, but rather that he did not know what to disclose.

After further cross examination by Mr Hamlin, the detective said the texts still confused him, but after reading them multiple times he could see the importance of some specifics raised in the Appeal Court.

In summarising the appeal, Mr Hamlin submitted that Witness X’s texts to the detective amounted to an alibi and may have made a significant difference to the trial.

He said a series of errors flowed from the detective not taking the witness statement and disclosing the texts, including that the witness was not made available for cross examination when the Crown case relied heavily on hearsay.

Mr McCoubrey submitted that Witness X made up her statement.

He said she was speaking freely and easily to police about other issues and it did not make sense that she would suddenly add the evidence about Natana being at her house.

The justices reserved their decision.