Several high-profile property developers are being investigated for bribing Huang Yao, the top political adviser in Guizhou province, who has been under a form of Communist Party discipline since October. Last week the Guizhou provincial Chinese People's Political Consultative Conference announced that four delegates were implicated in the investigation of Huang, including property developers Li Qinghong and Xiao Jiansheng, who have both been arrested, according to a report by China Broadcasting Net. Huang was put under shuanggui last year for a serious breach of party discipline - a euphemism for corruption. The investigation is continuing but so far shows that the 61-year-old chairman of the Guizhou CPPCC began receiving bribes in 1993, when he was made a member of the provincial party standing committee. He was then promoted to deputy party secretary of the province and became chairman of the Guizhou CPPCC in 2007. Huang was never in charge of property development but somehow got his fingers into it. With the opening up of the market, collusion between property developers and government officials has become a popular form of corruption on the mainland. It has led to the fall of many high-ranking officials, including former Shanghai party secretary Chen Liangyu . Huang is not the only top official from a provincial CPPCC to have been brought down by corruption. As the mainland stepped up its anti-graft campaign last year, two other provincial CPPCC chairmen were caught - Chen Shaoji from Guangdong and Sun Shuyi from Shandong . In another corruption case, former Supreme People's Court vice-president Huang Songyou, 52, stood trial in Hebei province yesterday, Xinhua reported. He faced charges for taking more than 3.9 million yuan in bribes from 2005 to 2008, while he was the Supreme Court vice-president. He was also charged with embezzling 1.2 million yuan in 1997 when he was president of the Zhanjiang Intermediate People's Court in Guangdong. There were no further details on the court case from state media yesterday, but earlier rumours said Huang was involved in a land-auction corruption case in Guangdong that brought down several of the province's top judicial officials, including Yang Xiancai, executive director of the Guangdong Higher People's Court. Four other senior Supreme Court judges have been implicated in Huang's case, with one placed under shuanggui and the other three still under investigation. The highest-ranking judge to be charge with corruption, Huang was arrested in 2008. According to the latest Supreme People's Procuratorate work report, more than 13,000 corrupt officials were found nationwide in 2008, of which 2,620 - about a fifth - were from the judicial sector.