Chinese authorities are to prosecute the former general manager of a leading credit rating agency for allegedly taking “massive” bribes, as Beijing vows to improve oversight of the industry in the wake of unprecedented bond defaults.

The Central Commission for Discipline Inspection announced on Monday that Jin Yongshou, former general manager of Golden Credit Rating, would be prosecuted for allegedly taking bribes from issuers covered by the agency and helping numerous companies improve their credit ratings.

The watchdog made the announcement a day after the People’s Bank of China pledged to improve its supervision of the country’s rating agencies. Last month there was a string of defaults by highly rated issuers that sent shockwaves through China’s $15bn public debt market.