A total of 37 provincial and ministerial level officials were put under investigation in 2015 - a year of "zero tolerance" for corruption, the authorities said on Saturday.
According to the Communist Party of China's Central Commission for Discipline Inspection (CCDI), authorities looked into the conduct of new provincial and ministerial level officials every month of 2015, Xinhua news agency reported.
The 37, including 10 from central government and nine from centrally - administered state - owned enterprises, came from 31 provinces, municipalities and regions, said the CCDI.
Of those probed, 13 of them, including a minister, were the most senior member of their departments.
In 2014, the number investigated was 38.
Since late 2012, the CPC has been waging an intense war against corruption.