An anti-graft official in Sichuan province has been placed under investigation after he was caught soliciting a prostitute.

The probe into Liu Rui, former director of Deyang city's discipline inspection commission, was announced on Thursday, a day after the country's core leadership called for more supervision of officials involved in the crackdown on corruption.

Liu, 53, was still head of the anti-graft watchdog when he committed serious disciplinary violations, namely soliciting a sex worker, according to Li Yong, a spokesman for the city government.