A senior official was found hanged on Sunday at his home in Guangzhou, Guangdong province, local media reported.
Police confirmed the death of Liu Xiaohua, deputy secretary-general of the Communist Party of China's Guangdong Provincial Committee, and ruled out the possibility of homicide.
No further details were revealed. Guangdong's top anti-graft body declined to comment.
Before being appointed to what would be his final post in March, Liu was deputy Party chief and mayor of Heyuan until 2011 when he became Party chief of Zhanjiang, a port city in Guangdong, and director of the city's People's Congress.
Liu's apparent suicide came as Guangdong's top anti-graft body expanded its investigation of officials suspected of corruption in the southern province, one of the country's economic powerhouses.
"Anti-corruption is a long-term and tough task in Guangdong and anti-graft bodies across the province will never lower their vigilance," said Huang Xianyao, Party chief of the Guangdong provincial Commission for Discipline Inspection, during a work conference in Guangzhou last week.
Huang urged anti-graft officials to do what they can to ensure clean and honest government operations to serve the province's economic development.
Earlier this month, Qian Fangli, chairwoman of the Zhuhai Committee of the Chinese People's Political Consultative Conference, and Liu Baihong, deputy mayor of Qingyuan, were put under investigation for suspected violations of Party discipline and accepting bribes.