A Victorian retiree has struck gold, unearthing a 2-kilogram nugget worth about $130,000 on the outskirts of the gold rush town Ballarat.

Key points: A retiree prospector has uncovered a hefty gold nugget in a Victorian field

A retiree prospector has uncovered a hefty gold nugget in a Victorian field He almost walked away from the site, having already unearthed a bullet

He almost walked away from the site, having already unearthed a bullet The $130,000 find comes amid something of a gold rush revival in the state

The amateur prospector was searching through old pastureland in a now 'top secret' location when his metal detector started beeping.

He started digging and quickly uncovered a .22 lead bullet.

Thinking that was that, he was about to move on — but his detector was "insistent" there was something else further down.

Located under 30 centimetres of wash under about 15 centimetres of clay was the whopping gold nugget, which has since been named You Wouldn't Believe It.

Mark Day of Gold Ballarat said the man, an amateur enthusiast and customer, had already received offers of $160,000 for his find.

"He was shaking like a leaf — he didn't know what to do with it," Mr Day said.

"He hadn't slept in three days."

The prospector, who wishes to remain anonymous, has since gone to ground and is refusing to reveal where he found his nugget.

'Like nothing I've ever seen'

Mr Day has been in the gold trade for 25 years and says it is the biggest nugget found by any of his customers.

"It's the biggest that they've told me about, anyway," he said.

It is not the prospector's first find either — he uncovered a 42-gram nugget earlier this year.

The prospector is delighted with his find. Understandably, he's declined to identify himself or the location he was searching in. ( Supplied )

Mr Day was one of the first calls the retiree made upon realising his huge find.

"I said I wasn't a buyer and asked him what he meant by big," Mr Day said.

"He said 'two kilos,' and I just said, 'you've got to be kidding!'

Former Ballarat president of the Prospectors and Miners Association of Victoria, Brian Robillard, says patience is the key.

"There's more people running around with detectors than I've ever seen before," Mr Robillard said.

"A lot of people jump into prospecting thinking they're going to get rich, like with this two-kilogram nugget, but you've probably got a better chance of winning Tattslotto".

But Mark Day remains circumspect.

"History tells us that big finds like this have happened in this area before, and even though they've been digging gold in this region for 150 years, it's still out there."

There's gold in them thar hills

It is believed more than 2.26 million tonnes of gold still remains underground in regional Victoria.

The state is currently in the midst of a gold rush revival of sorts, with gold production doubling in the past five years.

Fosterville mine in Bendigo, in central Victoria, has begun producing a reserve of 76.5 tonnes of high-quality gold, while the Stawell Gold Mine restarted operations in north-west Victoria last year after almost collapsing in 2016.

Fosterville has been in operation since 2005. In 2015 the mine started producing higher-grade gold. ( ABC Central Victoria: Sian Gard )

The Fosterville Mine in Central Victoria is expected to produce between 16.1 and 17.2 tonnes of gold each year for the next three years.

But that hasn't stopped surface-based prospectors.

Peter McCarthy, a former mining engineer and one of the people behind the reopening of the Castlemaine Goldfields mine in Ballarat, said the retiree's two-kilo discovery did not come as a surprise.

He says there's plenty more gold to be found - but the number of people looking for it has also increased.

"There's certainly more people looking now than there were six-to-nine months ago," Mr McCarthy said.

"It's a bit seek and yee shall find. The Victorian Government has done some work on the statistics of deep gold and they say there's an awful lot — perhaps as much as already been found, still to be found again at depth".

"The old timers had no way of finding that gold because it was covered by 50 to 100 metres of clay and sand and gravel."

Retired mining engineer Peter McCarthy says there is plenty of gold still be unearthed in regional Victoria. ( ABC Central Victoria: Sian Gard )

All just a little bit of history repeating

In the 1850s, Australians and immigrants from countries including the United Kingdom, United States and China flocked to regional Victoria, setting up makeshift camps across the goldfields in search of their fortune.

The world's largest known nugget, The Welcome Stranger, was found in 1869 at Moliagul, north-west of Melbourne, and weighs a whopping 65.3kg.

The largest nugget to be found in the 20th century with a metal detector was the Hand of Faith, which was located in nearby Kingower in 1980 and weighed 24.6kg.

This most recent find comes about a month after a young girl stumbled across a gold nugget worth about $30,000, while walking her dog near Bendigo, while another 1.4kg nugget was found near the West Australian mining city of Kalgoorlie-Boulder in May.

As for the Ballarat-based prospector behind You Wouldn't Believe It, he's bought himself a new metal detector and is back scouring in his secret spot.

"He certainly thinks there's more gold out there," Mr Day said.