Real estate prices in major cities in China have suddenly gone from bust to boom, a leading real estate expert said.

"The bidders have gone irrational," said Pan Shiyi, chairman of SOHO China, a large property investment company.

In one instance, a land parcel in Beijing was taken off the market 15 months ago due to a lack of interest, the China Daily reported. But this week, the same parcel broke a record for a single-parcel price, selling for $585 million, the newspaper said.

"We used to talk about monthly price growth, but recently, it's more about daily change," a broker with Homelink told the newspaper.

Other cities are reporting similar booms, which were pushed by two government interventions, the newspaper said.

In October 2008, the central bank gave banks permission to offer first-time homebuyers a 30 percent discount in mortgage rates. This spring, the government reduced the minimum capital fund requirement for developers from 30 percent to 20 percent of the investment.

Not everyone is pleased prices are soaring.

"To people who haven't bought a home, like me, we really don't know whether we should keep waiting or jump onto the wagon," said Yang Anjing who works for a consulting firm in Guangzhou.