The jury in a District Court trial of five people accused of a million-dollar gold theft in WA's Goldfields has returned a verdict of not guilty on all counts.

After hearing evidence from eight witnesses, the four-week trial ended on Tuesday with the group's acquittal after barely two hours of deliberations.

The jury returned not guilty verdicts on all 10 charges related to the alleged theft of 8,465 tonnes of gold-bearing ore from the Greenfields Mill near Coolgardie four years ago.

The gold the ore produced, and which was sold to the Perth Mint, was worth $1.17 million based on metal prices at the time. 

Among the accused was the former general manager of gold miner FMR Investments, 42-year-old Patrick Rhyan Keogh, who did not speak to reporters as he walked out of the Kalgoorlie courthouse. 

Mr Keogh testified that FMR Investments founder Peter Bartlett gave him permission to profit off a waste stockpile sometime in late 2012 or early 2013, and that he "didn't have to ask him twice", before it was treated at Greenfields Mill between December 2018 and January 2019.  

Mr Keogh and former Greenfields Mill manager Christopher Robert Burns, 76, had both pleaded not guilty to stealing as a servant and other charges relating to the proceeds of an offence.

Simon Leslie Gash, 57, and his business partner, Russell Wilson Holden, 51, had pleaded not guilty to money laundering and fraud charges over their alleged involvement via private company Aqua Alluvial Pty Ltd.

Former mill superintendent Morgan Whitney Dombroski, 33, had also pleaded not guilty to possessing $5,050 suspected of being unlawfully obtained, which the prosecution alleged was leftover from a $90,000 cash payment she received from Mr Burns.

Mr Keogh's father Aidan said was relieved when he spoke to reporters outside Kalgoorlie courthouse.

"I think the verdict was a just and proper verdict, it should never have happened but that's what happened," Aidan Keogh said.

"Anyhow, it's a good result."

Aidan Keogh said he was no longer on speaking terms with Mr Bartlett, who testified against his son and told the court they had been close friends for 40 years.

"Um … I don't perhaps think so … for a number of reasons no, no, I think we'll just let that pass," Aidan Keogh said.

Defence lawyer David Grace KC represented Mr Gash in the four-week trial and spoke to reporters outside court.

"Very pleased obviously, my client's very pleased and very happy the jury gave the matter all the due consideration the matter deserved," he said.

"The client [Mr Gash] always believed in his own case and his own innocence, so I am very happy for him."

During the trial, Mr Grace said his client had only relied on "handshake agreements" for four previous milling campaigns he had done at Greenfields Mill, telling the jury that a "man's word is gold".

There were reports during the trial that some of the legal teams' fees were upwards of $12,000 a day. 

Mr Grace said the legal bill would be considerable.

"I can't estimate that, but it almost certainly will be, yes," he told the ABC.