A review of corporate and regulatory records indicates that the prime minister's relatives, some of whom have a knack for aggressive deal-making, including his wife, have controlled assets worth at least $2.7 billion, it said.

The Times' websites in English and Chinese were blocked in China on Friday morning, and searches for the New York Times as well as the names of Wen's children and wife were blocked on China's main Twitter-like microblog service.

Wen's mother, siblings and children have amassed the majority of the wealth since Wen was named vice premier in 1998, the Times reported. Wen was promoted to the premiership in 2003.

Giving one example, the Times said partnerships controlled by Wen's relatives and their friends and colleagues held up to $2.2 billion in stock in Ping An Insurance (Group) Co of China Ltd in 2007, the last year those stock holdings were disclosed in public documents.

Wen's 90-year-old mother had one investment in Ping An that was worth $120 million five years ago, the newspaper added.

The Times said it presented its findings to the Chinese government for comment. The Foreign Ministry declined to respond. Members of Wen's family also declined to comment or did not respond to requests for comment, the Times said.

The Foreign Ministry and State Council - China's cabinet, of which Wen is nominally the head - did not immediately respond to requests for comment.

The private lives of Chinese leaders as well as their assets are kept under wraps, with personal details considered state secrets.

Still, cases against lower-level officials, often exposed by Chinese media, and reports on senior officials by western and Hong Kong news organisations, underscore the extent to which those with power profit from their standing.

Occasionally, top officials are caught and prosecuted.

In the biggest political scandal in China in decades, now-disgraced senior party leader Bo Xilai, whose wife was convicted of corruption and murder in August, has been expelled from the party and stands accused of corruption, bribery and sexual promiscuity.

Bo was expelled from China's parliament on Friday and is expected to stand trial in the near future.

The extended family of Xi Jinping, China's current vice president who is expected to be named head of China's Communist Party next month and president of the country in March, has also amassed great wealth, according to an earlier news report.

Xi's relatives have investments in companies with assets of $375 million, and an 18 per cent indirect stake in a company with $1.7 billion in assets, Bloomberg news reported in June.

Bloomberg's website has been blocked in China since that report was published, underscoring the sensitivity of the Party and government towards such revelations about top leaders.

In the case of Wen and his relatives, the names of family members have been hidden behind layers of partnerships and investment vehicles involving friends, work colleagues and business partners, the New York Times said.

It said Wen's family's holdings include a villa development project in Beijing, a tire factory in northern China, a company involved in building some of the venues for Beijing's 2008 Olympics including the Bird's Nest main stadium, and Ping An Insurance, one of the world's largest financial services companies.

Wen's younger brother has a company that was awarded more than $30 million in government contracts and subsidies for waste water treatment and medical waste disposal in some of China's biggest cities, and controls $200 million in assets in a number of companies, the Times said, basing its estimate on government records.