BEIJING: Relatives of China’s reformist premier have amassed huge riches during his tenure, according to a report on Friday that came as the Communist Party strives to clean house before a pivotal handover of power.

The New York Times report about the family of Wen Jiabao, who will be replaced in a 10-yearly leadership transition next month, coincided with an announcement clearing the way for the prosecution of disgraced leader Bo Xilai.

Beijing immediately dismissed the report as an attempt to tarnish Beijing, with foreign ministry spokesman Hong Lei telling reporters in response to a question on the article: “Some reports smear China and have ulterior motives.”

After a detailed investigation, the newspaper said that many relatives of the government’s number two had become “extraordinarily wealthy” during his time in office.

Investments by Wen’s son, wife and others spanning the banking, jewellery and telecom sectors were worth at least $2.7 billion according to an analysis of company and regulatory filings from 1992-2012.

The revelations come as a particular embarrassment for Wen, who is the standard-bearer of the Communist Party’s reformist wing and has campaigned against the rampant corruption that infuriates so many ordinary Chinese.

President Hu Jintao has also made fighting graft in the Communist Party a top priority, and the issue is sure to figure in the party’s 18th congress starting on November 8.

Ahead of the congress, the party proceeded with an unfinished item of business on Friday with the announcement that ex-Chongqing city boss Bo had been expelled from parliament and had his legal immunity lifted.

The decision to remove him from the National People’s Congress clears the way for Bo to be put on trial for corruption and other crimes related to the murder of a British businessman that led to his downfall.

The newspaper’s investigation darkens the clouds hanging over the Communist Party caused by the Bo scandal as the regime prepares to name successors to Wen and Hu to steer the world’s second-largest economy for the next decade.

Next month’s congress will culminate in the unveiling of a new politburo that is expected to see Vice President Xi Jinping promoted to Communist Party general-secretary, in place of Hu.

Xi was the subject of a June investigation by financial news agency Bloomberg which alleged that his relatives had also built up a giant portfolio of investments in property and stocks worth hundreds of millions of dollars.

Public anger about corruption and cronyism is on the rise in China, fanned by social media that helps spread stories of official wrongdoing despite the best efforts of the country’s powerful censors.

All online searches related to the New York Times were blocked on Friday, as were references to Wen and his family.

The investigation covered alleged dealings by Wen’s younger brother and brother-in-law, as well as his businessman son—one of the wealthy so-called princelings with access to the upper reaches of the party.

The business of Wen’s wife, Zhang Beili, a well-known jewellery and gemstone expert, had become “an off-the-charts success only as her husband moved into the country’s top leadership ranks”, The Times said.

His elderly mother meanwhile owned a stake valued at $120 million in 2007 in the enormous Ping An insurance giant, which benefited from reforms during Wen’s tenure, according to the newspaper.

It gave no figure for the family’s net worth now, but calculated the value of the assets they had controlled over the period examined. No holdings were found in Wen’s name.

Speculation of a hidden fortune has been circulating for years, fuelled by US embassy documents from 2007 made public by WikiLeaks that alleged influence-peddling by members of Wen’s family.

A spokeswoman for the New York Times, Eileen Murphy, expressed disappointment that access to the company’s English– and newly launched Chinese–language web-sites had been blocked as a result of the investigation.

“We hope that full access is restored shortly, and we will ask the Chinese authorities to ensure that our readers in China can continue to enjoy New York Times journalism,” she said in a statement.

The website of Bloomberg is still blocked inside China after its June expose on Xi.