The massive data leak from a Panama-based law firm dealing with offshore shell companies has implicated relatives of no fewer than eight current and former members of China's Politburo Standing Committee, analysis of the data showed Wednesday.

The leaked internal documents from Mossack Fonseca & Co. showed that family members of three current members of the top body of the Communist Party of China, including President Xi Jinping, had been involved with shell companies dealt with by the firm, along with family members of five former members.

A grandson-in-law of China's founding father, Mao Zedong, is also among those implicated.