As part of the sweeping campaign against corruption since late 2012, 120 former officials at or above vice-ministerial level were investigated for graft in the past five years, compared with 30 in the previous five years, according to the top procuratorate.

A total of 254,419 officials were investigated for duty-related offenses, such as bribery or dereliction of duty, from 2013 to 2017, up by 16.4 percent compared with 2008 to 2012, Cao Jianming, procurator-general of the Supreme People's Procuratorate, said in a work report to the top legislature on Friday.

National lawmakers said the achievement reflects the central leadership's strong determination to eradicate corruption, and they are expecting that ongoing reform of the national supervision system will further consolidate anti-corruption efforts.

Among the "tigers" felled by the anti-graft campaign were Zhou Yongkang, a former member of the Standing Committee of the Political Bureau of the Communist Party of China Central Committee; Sun Zhengcai, former secretary of the Chongqing Municipal Committee of the CPC; and Ling Jihua and Su Rong, former vice-chairs of China's top political advisory body, Cao said.

The court system has concluded graft cases involving 101 former officials at or above vice-ministerial level in the past five years, according to the work report of the Supreme People's Court delivered by Chief Justice Zhou Qiang to the National People's Congress on Friday.

"We've maintained high pressure on graft and improved our judicial mechanism for handling job-related crimes," he said.