The third day of the trial has now concluded.

Tomorrow the trial will resume at 10am with an expert witness from Canada, who will give evidence via video link.

Join us tomorrow for live updates of the ongoing court case.

Polkinghorne's lawyer Ron Mansfield KC and Sergeant Christian Iogha spent several minutes bogged down in the minutiae of when certain forensic staff or detectives arrived or left the property during the days-long scene examination.

Iogha, under cross-examination, said staff pored over the property, taking samples from all over and analysing any samples or fluids found inside.

"Can we agree that the New Zealand police were looking for any evidence of a struggle or an assault at the house?" Mansfield asked.

Iogha said police were keeping an open mind and would have been open to any evidence that might have disproved a struggle or an assault.

Mansfield countered, saying Iogha did not have an open mind and was adamant the death was suspicious from the moment he conducted his tension test on the orange rope.

Police spent at least nine days at the home in Upland Rd in April 2021. Mansfield, in questioning, claimed the length of the search was unprecedented and suggested police were desperate to find evidence of wrongdoing or a struggle.

"The size of the house was a lot larger than a regular New Zealand home," Iogha said in response.

"We have a duty to the public to make sure that we conduct a thorough investigation."

Justice Graham Lang has called an end to today's proceedings.

Tomorrow the trial will resume at 10am with an expert witness from Canada, who will give evidence via video link.

Earlier this afternoon, jurors were shown a photo of a meth pipe that was found in Philip Polkinghorne's bedroom during the lengthy search of his home. He pleaded guilty earlier this week to possession of the pipe.

In response to questioning from defence lawyer Ron Mansfield as to the legal basis for their continuing presence in the home, after police had begun to suspect the death was suspicious, Sergeant Christian Iogha said: "It was a very complex situation."

In his notebook, he had written Detective Sergeant Franich believed there was not enough evidence for a search warrant, but that they should hold the address under the consent of the owner.

Mansfield asked who in the Criminal Investigation Branch (CIB) team asked for Polkinghorne's consent to search the home. 

Iogha said he was not sure, and confirmed he did not.

"It's fair to say isn't it that none of the CIB staff despite being aware of the need to approach Dr Polkinghorne for his consent, actually did that?" Mansfield asked.

"I don't know if anybody asked," Iogha replied.

"Can we agree that no one actually tried?" Mansfield asked.

Iogha again said he was not sure if anyone did.

Mansfield has spent several minutes grilling Iogha on the legal basis for their search of Polkinghorne's home after they had deemed the death suspicious.

The defence lawyer's point is that he believes police no longer had a legal basis under the Coroner's Act, given they suspected the death was not a suicide after conducting their contentious rope test.

Mansfield is suggesting police should have obtained consent from Polkinghorne to continue to hold the house, or immediately obtained a search warrant.

"Had a decision been made not to tell Dr Polkinghorne that the death of his wife was being treated as suspicious until after the interview?" Mansfield asked.

"There was no talk of it, no," Iogha replied.

Ron Mansfield KC is beginning his cross-examination of Sergeant Christian Iogha. 

He is questioning him about his notes regarding his involvement with the scene.

Iogha said they showed his team, including Detective Ilona Walton and Detective Sergeant Mark Franich, arrived about 8.55am.

Mansfield is asking why Iogha was not immediately made officer in charge of the scene. That was a decision for Detective Sergeant Franich, Iogha said.

"Was there some other reason why you couldn't do it?" Mansfield asked.

Iogha was made officer in charge of the scene on April 6, the day after Hanna's death.

Iogha  said he had been in the CIB just over a year as of April 5, 2021, in response to Mansfield's questioning.

He had attended about 20 suicides and about half of those were hangings, Iogha said.

They had all been full hangings where the deceased's entire body weight was suspended, he said.

He eventually left the home on the afternoon of April 13, after 4pm, Iogha said.

Police were still present and Iogha said he simply handed over the role as officer in charge of the scene to another policeman.

He was unable to say when police finally released the home back to Polkinghorne, sparking incredulity from Mansfield, given Iogha's role in the wider investigation.

"I just want to understand from you when the address was released to Dr Polkinghorne," Mansfield said.

"You'll have to ask Detective Sergeant Reed," Iogha replied.

The defence lawyer and the detective then got bogged down in the dates of the scene examination, sparking some laughter from the gallery.

Mansfield asked if it was a very long scene examination.

"It's longer than normal, correct," Iogha said, adding that it was the longest such examination he had been a part of.

The sergeant said police were initially at the home under the Coroner's Act, making inquiries to confirm the death was in fact a suspected suicide as reported.

Mansfield moves on to the rope tension test that was the source of tense cross-examination of another detective earlier today.

The death was initially treated as unexplained, Iogha said.

He was unable to say if the change in status of the death was reported to the coroner.

"Who told you that you were authorised to commence a search at that point?" Mansfield asked.

"Just... under the guidance of Detective Sergeant Franich," he said.

A photograph shown in court today illustrates the scene police found in Pauline Hanna's room that day, with sheets pulled out of the bed and an ottoman on its side.

The trial heard earlier the bed was missing a top sheet, and a slightly damp white sheet was found in a dryer.

Sergeant Christian Iogha also said testing showed a brown stain on a fitted sheet was likely to have been blood.

The trial has resumed for the final session of the day. 

Crown prosecutor Alysha McClintock continues to lead the evidence of Sergeant Christian Iogha, who was an officer in charge of the scene and conducted the "tension test" of the orange rope that became the centre of today's evidence and cross-examination.

Under questioning from Crown prosecutor Alysha McClintock, Sergeant Christian Iogha said police found a slightly damp, large white sheet in the dryer in the laundry.

The trial earlier heard the bed in the master bedroom was missing a top sheet.

There was also a range of wet items in the washing machine, including female clothing and tea towels, Iogha said.

“The washing didn’t appear that it had been there long," he said.

During their lengthy scene examination of the sprawling 370sq m Upland Rd home, police had ESR scientists conduct a 3D scan of the entire house.

McClintock is now playing that 3D computer-generated walk-through of the home for the jury.

She has paused the walk-through at the top of the steps near the balustrade where the orange rope was tied – the defence says by Hanna to hang herself, the Crown says by Polkinghorne to stage the scene as a suicide.

Silence reigns in the courtroom as lawyers, media and the dozens of people in the public gallery watch the fly-through video.

Sergeant Christian Iogha said police found a container in a drawer at the home with what they suspected was methamphetamine.

He said they used their portable drug-detecting Lumi device, issued to police in 2021 by ESR to detect drugs, to confirm it was most likely methamphetamine in the container.

At the start of the trial, Polkinghorne pleaded guilty to two methamphetamine-related charges that were previously suppressed.

On the evening of Tuesday 5, hours after his home had become a crime scene swarming with detectives and forensic specialists, Polkinghorne returned to the property after his lengthy police interview at the College Hill station.

He was escorted into the home so he could take a shower and grab some belongings, Iogha said.

Police remained at the home for eight days. They charged Polkinghorne with Hanna's murder 16 months later.

He asked to take a laptop from the scene.

Iogha said he told him that because "police had changed their reasoning for being at the scene", he was not able to take the device.

Also in the house, police found a butane lighter beside a box. Inside the box was a glass pipe of the type commonly used to smoke methamphetamine.

During his lengthy questioning by Crown prosecutor Alsyha McClintock, Iogha described finding meth in other parts of the house, including the office, where a snaplock bag containing the "white browny crystal substance" was found.

Sergeant Christian Iogha said police conducted fingerprint testing around Polkinghorne's bedroom.

Photos of the scene show an ottoman tipped over on its side.

Iogha said Polkihgorne told police the ottoman was on its side so he could use it to reach a cupboard above a wardrobe towards the ceiling. 

The Crown prosecutor asked if there was anything about the sheet on a bed that warranted further examination.

Iogha said there was a brown smudge on the fitted sheet.

It was later tested by a forensic scientist. The result came back that there was a highly probable chance there was blood present on the sheet.

There was no top sheet on the bed, Iogha said.