Among the law firm’s high-flying Chinese customers is Deng Jiagui, the brother in law of China’s paramount leader Xi Jinping, who has made anti-corruption a hallmark of his rule. Deng Jiagui acquired one offshore firm via Mossack Fonseca in 2004 and two more in 2009.

The companies were called Supreme Victory Enterprises Ltd., Best Effect Enterprises Ltd. and Wealth Ming International Ltd. It is unclear what the companies were used for. Supreme Victory was dissolved in 2007, and the other two companies had become dormant by the time Xi became Communist Party chief in 2012. Deng Jiagui did not respond to ICIJ’s requests for comment.

Another prominent client is the daughter of Li Peng, China’s premier from 1987 to 1998. Li is best known internationally for overseeing the bloody military crackdown on the 1989 Tiananmen Square pro-democracy protests.

His daughter, Li Xiaolin, and her husband own Cofic Investments, a British Virgin Islands company incorporated in 1994. In internal emails, Li’s lawyers say the firm’s funds came from helping facilitate the export of industrial equipment from Europe to China. The files show that ownership was cloaked for many years by use of so-called bearer shares, which are registered without names — if the bearer certificates for a company are in your hands, you own the company. Bearer shares have long been considered a vehicle for money laundering and other wrongdoing, and have been gradually disappearing worldwide as jurisdictions toughen regulations aimed at stopping the flow of dirty money.

The new generation of so-called red nobility seems to have learned about the offshore world at a young age. The granddaughter of Jia Qinglin, who served as the No. 4 member of the Politburo Standing Committee until 2012, has offshore assets. Jasmine Li Zidan became the owner of an offshore company called Harvest Sun Trading Ltd. in 2010 — when she was a freshman at Stanford University.

Since then, Jasmine Li has built a surprisingly large business for someone still in her 20s: her two British Virgin Islands shell entities were used to set up two companies in Beijing with total registered capital of $300,000. By having the two BVI companies own Li’s shares in the Beijing companies, she was able to keep her family name off the public registration documents.

The five other current and former Standing Committee members whose relatives are connected to offshore dealings are:

Zhang Gaoli, a current Standing Committee member, has a son-in-law named Lee Shing Put, who was a shareholder of three companies incorporated in the British Virgin Islands: Zennon Capital Management, Sino Reliance Networks Corporation and Glory Top Investments Ltd.

Liu Yunshan, a current Politburo Standing Committee member, has a daughter-in-law named Jia Liqing who was the director and shareholder of Ultra Time Investments Ltd., a company incorporated in the British Virgin Islands in 2009.

Zeng Qinghong, who was vice president of China from 2002 to 2007, has a brother named Zeng Qinghuai, who was the director of a company, China Cultural Exchange Association Ltd., that was incorporated first in Niue and then re-domiciled in 2006 in Samoa.

The late Hu Yaobang, who served as head of the Chinese Communist Party from 1982 to 1987, has a son named Hu Dehua who was shareholder, director and beneficial owner of Fortalent International Holdings Ltd., a company incorporated in the British Virgin Islands in 2003. Hu Dehua registered the company using his home address — the traditional courtyard home where his father lived while party chief.

Mao Zedong, who led Communist China from 1949 to his death in 1976, has a grandson-in-law who incorporated Keen Best International Limited in the British Virgin Islands in 2011. Chen Dongsheng is the head of a life insurance company and an art auction house and was the sole director and shareholder of Keen Best.

China’s Foreign Ministry did not respond to a faxed request for comment by ICIJ. Asked whether China plans to investigate any of the China-related companies or holdings revealed in the leaked documents, ministry spokesman Hong Lei told a regular press briefing in Beijing on Tuesday that he had no comment on the “groundless accusations.”