Walcha murder trial: Natasha Beth Darcy's CPR attempts heard on triple zero call in trial for murdering Mathew Dunbar

The 20-minute triple zero phone call from Natasha Beth Darcy was played in her murder trial in the NSW Supreme Court in Sydney on Thursday.

She's accused of sedating and gassing her partner, Mathew Dunbar, 42, who died in his bedroom on his 'Pandora' property in Walcha on August 2, 2017.

The jury heard the phone call, which had to be reconnected by the triple zero operator twice.

READ ALSO:

Darcy was heard telling the operator "he's got a bag over his head", and "he's been inhaling it, there was a tube going into the bag".

"He's still warm," she said.

Darcy told the operator she had turned the gas off from a helium tank in the room, and removed anything covering his face and mouth.

"He's not breathing, no, He's cold. His face is cold," she is heard on the call.

She was given instructions to perform CPR, and told paramedics were on the way. She told the operator her "ex-husband is the paramedic ... he's on tonight".

The jury heard Darcy made the call on the deceased's phone because she couldn't find her phone.

The Crown alleges she murdered Mr Dunbar for financial gain because she was the sole beneficiary of his $3.5 million 'Pandora' property.

It's the Crown case that Darcy searched 'how to commit murder' and if drugs and helium 'would show up in an autopsy' before she allegedly sedated and gassed Mr Dunbar.

The jury was also shown dozens of photographs of the crime scene at the Walcha farm.

Detective Senior Constable Graeme Goodwin detailed a series of photographs and interactive images of the house, and the bedroom, including where Mr Dunbar's body was found; the helium tank; as well as the Nutribullet-like machine that allegedly contained the cocktail of drugs.

Another witness, chartered account Kimberley Lisle, detailed evidence from Mr Dunbar's tax and financial statements covering the years leading up to his death.

She was questioned about his cash flow and financial matters that Mr Dunbar needed to complete his tax return.

When asked by Crown prosecutor Brett Hatfield if Mr Dunbar had a "relatively significant depreciation figure each year", Ms Lisle replied: "yes".

She told the court a small loss that had been accumulated over the years was not unusual for a farmer, and "it's probably not much of a loss" for the debt levels when compared with the increased value of the land.

Under cross examination, Ms Lisle agreed that in a seven-year time period "Mr Dunbar had spent quite a bit on capital equipment", when asked by defence barrister Janet Manuell SC.

Forensic accountant Scott Wallace was the fourth witness to take the stand in the trial and detailed examinations of bank account statements.

He said he found evidence of $6000 being transferred to accounts mentioning Colin Crossman - the estranged husband for Darcy - in 2016 for rent and mortgage payments.

"I couldn't locate any," Mr Wallace replied, when asked if there was anything returned from Mr Crossman in the accounts.

He noted that there was "much more, yes" spending on Mr Dunbar's cards, than Darcy's when questioned by Mr Hatfield.

The trial before Justice Julia Lonergan continues.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: