One investor had put a total price tag of HK$100 million on 34 parking spaces in a commercial building near Western, said Sean Tsoi, a dealer at property development and investment agency AGW Holdings Ltd, referring to an area just five minutes by car from the heart of Hong Kong's financial district.

The average price for each space in the building was about HK$3 million, higher than the cost of a small apartment in some areas of Hong Kong, which is home to the world's most expensive residential and retail property.

"Car parks have become a new hot item," said Hanson Lam, senior property consultant at Midland Realty. "They're overpriced and I worry that there might be a bubble."

Lam said prices of parking spaces had jumped 20 to 30 percent since the government's latest property curbs in October.

Developers such as Sun Hung Kai Properties Ltd (0016.HK), Hong Kong's largest property developer, and Cheung Kong (Holdings) Ltd (0001.HK), controlled by the city's richest man Li Ka-shing, had sold more than 2,000 new parking spaces over the past two weeks, said Wong Leung Sing, research associate director at Centaline Property Agency.

Wong said sales of new parking spaces had surged about 50 percent so far this month although he was not alarmed.

"It's a simple logic for investors: if you don't allow me to buy residential properties, then I will turn to parking spaces, and it's still more profitable than putting money in the bank," he said.

Hong Kong leader Leung Chun-ying, who took over on July 1, earlier this month expressed concern over the impact of hot money flows into the city after the U.S. launched a third round of quantitative easing in September.

"Capital is flowing into Hong Kong, into its property market. Some people buy luxury properties, we've seen soaring prices there ... money is also flowing into shops, commercial premises and car parks," Leung said.

An inflow of hot money forced the city's central bank to intervene last month to protect its currency band for the first time since the global financial crisis.

The government imposed property cooling measures on Oct 26 to rein in residential prices, which jumped 20 percent in the first nine months of this year. (Editing by Nick Macfie)

• A Permanent Economic Emergency