Chinese state media hailed the power of the Internet Monday after a probe was launched into a top state planner following an online expose, making him the most senior official toppled by social media.

Liu Tienan, deputy director of the National Development and Reform Commission, is being investigated for "serious disciplinary violations", state-run media said Sunday, after graft claims emerged online in December.

Chinese citizens have taken to Internet forums such as Sina Weibo, a Twitter-like service, in recent years to expose wrongdoing and to vent their anger over corruption.

A motley parade of lower ranking officials have gained widespread notoriety after their indiscretions spread like wildfire on the Internet.

"This is the true meaning of democracy and the rule of law which are developing in China," said an editorial in the Global Times newspaper Monday, under the headline "Public opinion empowers Weibo's effect".

"The focus of power of Chinese public opinion is further shifting towards the Internet," it added. "The Chinese Internet sphere is now one of the most influential in the world. The trend will only continue to grow."

But Chinese authorities still strictly control discussion online, with sensitive posts rapidly deleted and searches for unwelcome topics routinely blocked.

Liu, 58, is under investigation by the Communist Party organ tasked with probing corruption and other malpractice by party members, state media said Sunday.

Allegations against Liu, who was party chief of China's National Energy Administration until March, surfaced when Luo Changping, a journalist at the influential business magazine Caijing, accused him of improper business dealings late last year.

Luo claimed the official used his position to enrich family members. The energy agency denied those allegations at the time.

"It took me one year to verify all the allegations that were made against Liu," Luo posted on his Weibo account Monday, but added that publication of his full findings had been indefinitely delayed, without giving clear reasons.

"I beg all fellow journalists to have mercy when they are reporting about the story since I have to shoulder all the responsibilities, which can't be handled by an individual," he said.

China's newly-installed leaders have made tackling corruption a key policy, with President Xi Jinping saying there would be "no leniency" for wrongdoing.

Since his promotion after the Communist Party Congress last November, a range of officials have been exposed, including a police chief who was investigated for allegedly keeping twins as mistresses and giving one a local government job.

The mayor of Lanzhou, the capital of Gansu province, was pictured apparently wearing a range of expensive watches, and an official in the southwestern metropolis of Chongqing was sacked after a video of him having sex with a mistress spread online.