The price of gold has never been higher against the Australian dollar, and neither has the temptation to steal it.

Key points: The squad travels all over WA and the NT, inspecting every gold mine at least twice a year

The squad travels all over WA and the NT, inspecting every gold mine at least twice a year Mining companies have paid for the service since 1907

Mining companies have paid for the service since 1907 Stories of black sludge and murder have marked the Gold Squad's history

As gold miners from around the country gather in Kalgoorlie for the annual Diggers and Dealers mining conference, the Gold Stealing Detection Unit (GSDU) in the Goldfields city is as busy as it was when it began in 1907.

Back then, so much gold was being stolen in the rush years, the mining companies pleaded for the police to help combat the thefts.

"The commissioner of police said back then, 'I'll give you the detectives but the Chamber of Minerals, as it was back then, you pay for them'," explained current officer-in-charge of the GSDU, Detective Sergeant Chris King.

(From left) Detective Senior Constable Gavin Farley (who has left the unit), Detective Sergeant Chris King, and Detective Senior Constable Jared Pragnell. ( Supplied )

Both parties continue to honour that century-old agreement.

"All our operating expenses are paid for by the Chamber of Minerals and Energy, but the staff, we're from the WA Police Force," he said.

It's not always yellow and shiny

Just as gold mining has changed drastically from the days Paddy Hannan first found the yellow metal in Kalgoorlie, the way it is stolen has changed too.

"Back in the early days, gold was stolen in its raw form," Detective Sergeant King said.

"But now the gold process has changed so much with the way it's extracted, there's a lot of different areas that it can be stolen from in that process.

The GSDU has had some big hauls in recent times. ( Supplied )

"It's been stolen as ore straight out of the pit, in raw gold form as nuggets, and when it starts going through the chemical process it can be stolen in that process too and it doesn't even look like gold.

"To the average person it can just look like black sludge, but to us, we look at it and know it's gold-bearing ore."

Just two weeks ago, the unit seized about two kilograms of gold from a contract mine worker in the goldfields.

This 129-gram sample from a recent seizure is worth $9,000 at today's prices. ( Supplied )

It is safe to say that worker is no longer employed by the mine.

The gold squad, as it is known colloquially, travels all over Western Australia and the Northern Territory, inspecting every gold mine at least twice a year.

Chris King leads the current GSDU. ( ABC News: Rachel Pupazzoni )

"We investigate anything that goes on in a mine site," Detective Sergeant King said.

"That can be everything from gold theft, drug offences, assault, arson offences — anything that happens at a mine site, we investigate."

A bloody history

No-one has given more for the GSDU than Detective Inspector John Walsh and Detective Sergeant Alexander Pitman.

They were investigating suspected illegal gold smelting in outback Kalgoorlie in 1926.

"Back then they never used to tell anyone where they were going, since they had to have a certain amount of secrecy to do what they did," Detective Sergeant King said.

The men's bicycles were found after a search party went out to look for them when they did not return as planned.

John Walsh and Alexander Pitman's bikes. ( Supplied )

Detectives sort evidence after the murder of John Walsh and Alexander Pitman. ( Supplied )

Detectives examine the murder scene. ( Supplied )

"They were murdered by the two men they were investigating for illegally smelting gold," Detective Sergeant King said.

These days the unit is a small team of just three detectives and an analyst, but the hauls are just as significant.

"We've had some pretty good arrests over the years," Detective Sergeant King reminisced, without giving too much away.