A total of 30 officials at the ministerial level or higher have been placed under investigation for corruption or other job-related crimes over the past five years, China's top procurator said Sunday.

Prosecutors have investigated about 13,000 officials at the county level or above for job-related crimes since 2008, said Cao Jianming, procurator-general of the Supreme People's Procuratorate (SPP), when delivering a work report of the SPP at the first session of the 12th National People's Congress (NPC).

Great efforts have been made to punish and prevent corruption, Cao said.

Prosecutors took about 19,000 bribers to court over the past five years. They investigated about 36,900 administrative law enforcement officials and 12,894 judicial staff in a bid to fight judiciary corruption, according to his report.

The SPP set up a national anti-corruption hotline and website, and improved its work in collecting clues and protecting whistleblowers and witnesses, he said.

Since 2008, prosecutors, together with other law enforcement agencies, have seized a total of 6,220 escaped suspects of corruption cases.

A national database of bribery cases has been established and more than 2 million searches were conducted, according to Cao.

This year, prosecutors will continue to pay attention to graft cases which harm public interests, Cao said.

The top procurator also warned of outstanding problems in the work of prosecutors.

"A small number of prosecutors have abused their power, failed to follow the protocol in the work, or used their power to seek personal profits, which seriously damaged the credit of law enforcement," he said.

This year the SPP will work to curb corruption and misconduct among prosecutors and tighten supervision on senior officers of procuratorates, he said.