Image copyright Sina Weibo Image caption The topic page for the Panama Papers hashtag on Sina Weibo appeared to have been censored by Monday afternoon with at least 481 discussions blocked

China appears to be censoring social media posts on the Panama Papers document leak which has named several members of China's elite, including President Xi Jinping's brother-in-law.

Hundreds of posts on networks such as Sina Weibo and Wechat on the topic have been deleted since Monday morning.

The leaked papers, from Panamanian law firm Mossack Fonseca, reveal how the rich have used tax havens.

They mention Deng Jiagui, who is married to Mr Xi's older sister.

An investigative report by Bloomberg News in 2012 suggested that Deng and his wife had hundreds of millions of dollars in real estate, share holdings and other assets.

There are legitimate ways of using tax havens and offshore companies, although these entities are often used to hide the true owners of assets or avoid paying tax on the money.

Panama Papers reaction - latest

Censored terms

According to the International Consortium of Investigative Journalists (ICIJ), the Panama Papers show that Mr Deng acquired two offshore companies in 2009, at a time when Mr Xi was rising in politics.

It is unclear what the companies were used for.

The two companies were dormant by 2012, when Mr Xi was named general secretary of the Chinese Communist Party.

Mr Deng did not respond to requests for comment from the ICIJ.

State media appeared to black out the news. But many on microblogging network Sina Weibo and mobile chat network Wechat were discussing the topic on Monday morning, sharing Chinese translations of details of the story, including information on Mr Deng.

A hashtag created on the topic quickly trended.

Checks by the BBC found that by the end of the day many of those posts had disappeared, with at least 481 discussions deleted from the hashtag's Weibo topic page, and other posts shared on Wechat also deleted.

The website Freeweibo.com, which actively tracks censorship on Weibo, listed "Panama" as the second-most censored term on the network. The top censored term was controversial Hong Kong movie "Ten Years".

Image copyright Freeweibo.com Image caption The website Freeweibo which tracks deleted content said the second most censored topic was "Panama"

Besides Mr Deng, several other individuals among China's elite were also named in the papers.

They include Li Xiaolin, the daughter of former premier Li Peng, and Jasmine Li, the granddaughter of former high-ranking official Jia Qinglin.

Li Xiaolin owned an offshore company, Cofic Investments Ltd, incorporated in the British Virgin Islands, while Jasmine Li received an offshore company as a teenager, ICIJ said.

The two women did not respond to requests from the ICIJ for comment. Charles-Andre Junod, a lawyer who was a director for Cofic Investments, declined to comment but said he had always respected relevant laws.

China's Communist officials are discouraged from profiting from their ruling positions, and their family members are not supposed to profit from their ties, according to the Party's constitution.

Mr Xi has been conducting a sweeping crackdown on corruption since he took power as president in 2012, arresting hundreds of thousands of officials.

Panama Papers - tax havens of the rich and powerful exposed