Why? The investor hopes it will act as a hedge against a plunge in an overheated property market.

He is not alone. Demand for the precious metal is growing among the super rich, who are snapping up gold coins and bars.

At Perth Mint – Australia's only gold refinery and the world's second biggest producer after China – sales of gold coins and minted bars rose to 68,781 ounces in September, their highest since October last year.

Minted bars, which range from 1 gram to 100 grams, took the lion's share of the increase, rising 37 per cent to 12,238 ounces, with investors in Germany and the US the biggest buyers.

"The bigger the bar you buy, the lesser the premium per ounce, so what we are finding is the smarter investors are looking at the minted bars," Perth Mint wholesale manager Neil Vance said.

"It's at the price now ... where some of the investors are coming back into the market again."

The Perth Mint is not the only gold business to notice a surge in demand. The US Mint revealed this week that sales of gold coins more than doubled last month to 58,000 ounces, the highest since January.

The strong investor appetite comes after the gold price fell 6.1 per cent last month to $US1220.30 an ounce, its lowest level since January this year.

Mr Vance is surprised the price has continued to linger at nine-month lows, considering interest from investors is increasing and tensions in the Middle East are rising. (The gold price normally spikes during times of global uncertainty because it is traditionally considered a safe asset).

But Perth Mint's analysis and strategy manager Bron Suchecki said demand for larger bars – 1 kilogram or more – needs to regain momentum before the world gold price starts to appreciate.

He is seeing promising signs with Asian buyers, who account for about 80 per cent of Perth Mint's sales by volume, returning to the market.

Mr Suchecki said buyers from China and India buy the 1-kilogram bars, which are worth about $45,000 each and are melted down to make jewellery and other items.

"That demand has been off, probably up until the last month. Premiums were quite low and there wasn't a lot of interest," Mr Suchecki said.

"But as soon as prices weakened down to these $US1200 levels, we have seen a real pick-up in the demand for 1 kilogram bars out of China, so premiums have recovered quite strongly."

Mr Tremaine, managing director of Guardian Vaults which operates in Melbourne and Sydney, said the 1 kilogram blocks were also popular with investors. Most of his clients store a mixture of those bars and coins and smaller blocks.

"The typical investor looks at it from an insurance perspective," Mr Tremaine said.

"They like the smaller bars and coins because they can provide immediate liquidity in the event that something goes wrong and they have the bigger ones as an insurance policy.

"They hold them in case ... the market collapses."

He said one of his clients, a property investor, was buying about $250,000 of bullion a month as hedge against a plunge in the housing market.

National house prices have risen by 10 per cent in the past year, but by 12 per cent in Melbourne and 15 per cent in Sydney. The surge has prompted the Reserve Bank to start drafting new regulations to scoop some of the investor froth off the property market.