Liu Tienan, deputy head of the National Development and Reform Commission, China's top economic planner, is under investigation for suspected "grave violations of discipline", China's top anti-graft authority has revealed on its website.

The investigation of Liu, who was also director of the powerful National Energy Administration until March, is a fresh sign of the new leadership's zero-tolerance toward corruption and its vow to hold violators accountable no matter who they are.

On Dec 6, Luo Changping, deputy editor-in-chief of Caijing, a popular investigative magazine, alleged in his real-name micro blog that Liu was involved in multiple offenses, including huge bank loan frauds and fabrication of his academic qualifications. Luo also accused Liu of having shady ties with a businessman whose company, which includes Liu's wife and son as shareholders, bought and merged many State-owned paper manufacturers.

The information office of the National Energy Administration dismissed the allegations the same day, saying they were "pure slander".

The absence of an authoritative voice from the country's anti-corruption watchdog over the past months, together with Liu's appearance on some official occasions since the accusations, has exacerbated public bewilderment about the truth.

Liu is the first ministerial-level official to be investigated as a result of corruption claims on the Internet. His confirmed investigation is evidence that the authorities are serious about fighting corruption.

The investigation into Liu comes as China's new leaders have vowed to root out corruption, which is seen as a threat to the ruling Party's public support if unchecked.

Since China's new leadership has shown its determination to root out corruption since it took office, the public has launched a fierce anti-corruption campaign on the Internet, and several lower-level officials have been investigated and brought to justice based on evidence of their corruption posted on the Internet.

Liu's investigation supports Party chief Xi Jinping's promise to crack down on both corrupt "flies" and "tigers". The case also inspires hopes that the authorities and the public can work together in the joint fight against pervasive corruption.