Yang Weize, former Party chief of Wuxi, speaks at a meeting in Nanjing, Jiangsu province on June 19,2013.[Photo/IC]

On Sunday, Yang was taken to Beijing by high-speed train from Nanjing, one of themost important cities on the Yangtze River Delta. He had been the Party chief of the city since 2011.

Yang's wife and his secretary were taken away by the discipline inspection department on the same day, Chinese media reported.

His wife allegedly participated in several construction programs when Yang was mayor of Suzhou, Jiangsu province, including a viaduct that used inferior materials and had problems with its foundations.

Yang's alleged mistress, Yu Minyan, who was the director of the publicity department of Wuxi New Area, was also taken away, according to an official who did not want to be identified. The two were said tohave a daughter.

Chinese media also reported that Yang was investigated because of a report by Gao Dezheng, a former deputy governor of Jiangsu province and the father-in-law of Nanjing's former mayor Ji Jianye.

CangWei in Jiangsu contributed to this story.