The fate of $60,000 of gold stolen from a West Australian mine site by three men having a barbecue is set to be decided by a Kalgoorlie court.

The rare gold nugget was stolen from a live mining tenement near the ghost town of Kunanalling, 32 kilometres north of Coolgardie, on June 4 last year.

Andrew Mark Warren, Stephen Lindsay Rowe and Michael James Forward pleaded guilty to attempting to defraud tenement owner Evolution Mining by stealing the gold.

A fourth man, Glen Stephen Rutherford, pleaded not guilty to any involvement in the theft.

Warren and Forward were due to be sentenced for the theft in the Kalgoorlie Magistrates Court on Monday, only for sentencing to be delayed until March 27 by Rowe's guilty plea.

Police prosecutor Thomas Banyard told the court he would also lodge an order for all gold recovered to be forfeited to the State Government.

The ABC understands the prosecution will argue that because the gold was stolen from under the ground, it remains the property of the state, rather than Evolution as the tenement holder.

"My understanding is the mining company loses out," Senior Constable Banyard told the court.

Magistrate John O'Sullivan said the renewed delay would give Evolution the opportunity to make counter-submissions to the prosecution's claim.

An Evolution spokesman said the company was monitoring the case, but "it would not be appropriate to make any further comment as the matter is still before the courts".

Men stopped for barbecue, stumbled onto gold

Earlier, the court heard the men had been on an unsuccessful prospecting trip when they stopped at Kunanalling for a barbecue.

Senior Constable Banyard said the men decided to explore the bottom of a disused mining pit nearby, where one of them stumbled over the large chunk of gold.

He said the men then used their metal detectors to recover more than a kilogram of gold, worth an estimated $62,390.

Detectives said the largest specimen — a rare gold leaf-type nugget — was smashed to pieces.

While the move allowed the men to divide the gold into 300 gram shares, it potentially cost them up to three times the nugget's estimated value, due to its status as a potential collector's item.

"It may have seemed like they were winning the lotto, but they did not have permission to be on the tenement or remove the gold," Senior Constable Banyard told the court.

Social media boast alerted police

The men's decision to pose with the gold for a Facebook photo eventually proved a critical error, with the Gold Stealing Detection Unit (GSDU) alerted to the theft.

Senior Constable Banyard said GSDU detectives seized 675g of the gold from a property in Boulder, while 300g was sold to a Kalgoorlie prospecting business.

Forward's defence counsel Carmel McKenzie said her client voluntarily handed 164g of gold to the GSDU.

"He accepts that he ought not to have taken the gold," Mrs McKenzie said.

She said Forward had lost his job with the Shire of Coolgardie as a result of the charges.

Warren's defence lawyer Alisdair Putt said "there was no indication of a sophisticated plan for offending".

Magistrate O'Sullivan released all three men on bail ahead of their sentencing.