TUCKED away beside the ornate entrance of the Savoy hotel in central London are the discreet premises of ATS Bullion. Over the past few days, staff have witnessed an unprecedented phenomenon: queues.

The customers are wary savers looking to build their own solution to the global financial crisis and the parlous state of the banking system. They are buying gold.

"There has been enormous demand," said Sandra Conway, managing director at ATS, one of Britain's leading gold coin and bar merchants. "There are very few sellers of physical gold and we have actually had queues of people today."

The world's makers of gold bars and gold coins are flat out to try to keep up with this surge in demand, but stocks are dwindling, especially of Krugerrands.

Named after Paul Kruger, who led the Boer resistance to the British in the 1899-1902 Boer War, the coins were first minted in South Africa in 1967.

Although it was illegal to import them into Britain during the 1970s and 1980s because of apartheid, they have become one of the world's most widely circulated gold coins. But the coins are becoming more scarce as investors snap them up.

As a result, the Rand Refinery is operating seven days a week, as is the Austrian mint, which produces the popular Vienna Philharmonic coin.

The US Mint, responsible for ensuring adequate US coinage since 1792, has halted sales of its American Buffalo solid 24-carat gold coin because the mint was running out of supplies.

It is also limiting the availability of its 22-carat American Eagle alternative.

Canny investors had also noticed that both one-ounce coins cost less than an ounce of gold on the open market at the time, making them tempting to anyone wanting a quick return.

Having broken through $US1000 earlier in the year, gold has retreated slightly and is trading at about $US880 an ounce. But the 2007 American Eagle one-ounce coin was going for $US789.95 while the 2006 Buffalo coin cost $US800 — offering the potential for $US80-90 instant return.