China's internet regulator denounces its former chief now under investigation

China's internet regulator had said it will purge the "evil influence" of its former top official who the ruling Communist Party has put under investigation for suspected corruption.

The official, Lu Wei, was suspected of serious discipline breaches, the Central Commission for Discipline Inspection (CCDI) announced on Tuesday.

Lu, a colourful and often brash official by Chinese standards, was at the height of his power seen as emblematic of China's increasingly pervasive internet controls.

The Communist Party referred to him as the "first tiger" taken down after a congress in October, when President Xi Jinping pledged that his anti-graft campaign would continue to target both "tigers" and "flies", a reference to elite officials and ordinary bureaucrats.

Lu's former agency, the Cyberspace Administration of China (CAC), held a meeting on Wednesday in which it called its former chief "a typical two-faced person" who had "seriously polluted" its political environment.

"Lu Wei cannot represent CAC's image. He precisely undermined CAC's image," the agency said in statement published late on Wednesday.

The CAC would "draw profound lessons" from Lu's breaches and "thoroughly purge Lu's evil influence", it said.

The CCDI said in a separate commentary on its website on Thursday that the investigation of Lu was a potent sign that the party would not let up on its fight against wayward officials.

"One must not think that no one will ask today about yesterday's crimes," the CCDI said.

It was "nonsense" to think the party would "let bygones be bygones", it said.

Xi has waged war against deep-rooted corruption since taking office five years ago, punishing hundreds of thousands of officials.

Lu worked his way up though China's official Xinhua news agency before becoming head of propaganda in Beijing and then moving to internet work in 2013. He later became a deputy propaganda minister.

But his downfall, foreshadowed by his June 2016 replacement as head of the internet regulator and the loss of his other posts, is unlikely to signal a reversal of internet control policies, which have been tightened under his successor, Xu Lin.

The government has blocked sites it thinks could challenge party rule or threaten stability, including sites such as Facebook and Google's main search engine and Gmail service.