A Hainan High People's Court vice-president dubbed "the richest judge in China" has been expelled from the Communist Party of China and removed from her post for alleged graft and involvement in her ex-husband's business empire, the Party's provincial political and legal affairs commission said on Saturday.

Zhang Jiahui has been placed under investigation for suspected serious violations of laws and regulations after a joint investigation was launched in May following reports about Zhang and her ex-husband's suspected corruption. Zhang's ex-husband, Liu Yuansheng, has also been under police investigation on suspicion of law violations.

Zhang filed false information to the Party and asked others to collude with her to devise a consistent story, the Hainan Commission for Discipline Inspection of the CPC said on Saturday, adding that she also deliberately planned to hide from the anti-graft agency's investigation.

She had also interfered with judicial activities, the graft watchdog said, and had taken advantage of her position to seek benefits for others and receive huge amounts of property.

Zhang, 54, came under scrutiny after Liu, who has interests in 26 companies, took a business associate to court for alleged extortion. In a court hearing on April 30, the business partner, Yi Zhenwu, said Liu owed him about 22.6 million yuan ($3.2 million) from a hotel construction contract. To force Liu to pay up, Yi said he secretly recorded videos of Zhang gambling on mahjong and audio of Liu boasting how he manipulated the stock market and gamed government subsidies.

On May 11, two other business partners of Liu held a news conference in Shanghai accusing the couple of accumulating a huge amount of assets by deceiving their business associates.

"Zhang wants to climb the political ladder while becoming rich. By taking advantage of her role in the legal system to support Liu's business expansions, she's become the richest court judge in China," they said in a statement.

According to the police investigation, Zhang has 14.3 million yuan in assets under her name and jointly owned assets of 16 million yuan, while Liu has built a business empire worth 1.8 billion yuan.

The couple arrived in Hainan in 1992 after they were employed by the Hainan Intermediate People's Court. Liu left the court in 1995 and became a lawyer two years later. He then decided to run his own business. In 2005, Zhang was transferred to the Hainan High People's Court and later became a civil court judge.

According to the provincial political and legal affairs commission, Zhang chose not to disclose facts about her husband's businesses when she was required to report her personal details as a part of anti-graft efforts in January 2016. The couple divorced in March 2017.

Zhang had also broken the law by organizing people to play mahjong and gamble since 2011, it said, and had also violated discipline by using a private banquet hall set up by Liu to organize dinner parties.