BEIJING (AFP) -- The number of dollar billionaires in mainland China has passed 300 for the first time, an annual ranking of wealth in the world's second-largest economy showed Wednesday.

The Hurun Report, a luxury magazine publisher, named property tycoon Wang Jianlin as China's new richest person, saying he had more than doubled his worth to $22 billion.

There were a total of 315 dollar billionaires in the country, it said, up 64 from a year ago.

The average fortune of the top 1,000 stood at $1.04 billion -- more than double their $440 million during the global financial crisis five years ago.

But some were dogged by scandal.

Three of last year's 10 richest people in Chengdu, the capital of Sichuan, have been detained amid a corruption crackdown in the province.

Two others on the list are in prison, while Xu Ming, who joined this year at No 676 with $490 million, was a key witness against Bo Xilai last month in China's biggest political corruption trial in decades.

According to court transcripts, Xu said he gave the former senior politician 21 million yuan ($3.4 million) in bribes, including purchasing a villa in the French resort of Cannes for Bo's wife.

Real estate businesswoman and recent divorcee Wu Yajun fell from No 8 to No 22 and her wealth dropped nearly a quarter to $4.6 billion after she gave her ex-husband $3 billion -- propelling him into the Top 50 in his own right.

Hurun called the transaction "the most expensive divorce settlement from a wife to her husband".

Inclusion on the Hurun rich list can be a mixed blessing, according to Oliver Rui, professor of finance and accounting at the China Europe International Business School in Beijing.

Market values of companies controlled by those on the rich list drop "significantly" in the three years following their appearance, he said in a research paper.

"Furthermore, due to public pressure, the government tends to scrutinise the rich list entrepreneurs and their affiliated companies more closely."

Among businesspeople on the list, 16.95 percent were subsequently "charged, investigated or arrested", compared to 6.84 percent among those who were not included, he found.

"Investors in China regard entrepreneurs being included on the Rich List as bad news," he said.

Real estate was the biggest source of ultra-rich fortunes in this year's list, led by Wang, whose conglomerate Wanda Group recently also acquired the US cinema chain AMC Entertainment and a luxury British yacht builder.

But Lei Jun of mobile phone maker Xiaomi rose the fastest on the 2013 rankings after his worth shot up seven-fold to $2.6 billion.

Wang was also named as China's richest man by Forbes magazine earlier this week, which estimated his wealth at $14 billion.