China's judicial authorities said Sunday the country had maintained "high pressure" on corruption to press on with an anti-graft drive lasting more than three years.

A total of 22 Chinese former officials at ministerial level or above, including former Chinese leader Zhou Yongkang, were prosecuted in 2015, while 41 were subject to investigation, a report on the work of the Supreme People's Procuratorate (SPP) read.

Another report on the Supreme People's Court, meanwhile, said courts had concluded trials for Zhou and 15 other senior officials, showcasing "the Party and the country's resolute determination in cracking down on corruption," it said.

Both reports were made public on Sunday morning, shortly before a plenary meeting of the annual session of China's top legislature.