* Top graft-buster Wang second most powerful person in China - expert
* Wang proposed lifting of immunity of Politburo Standing Committee members - source
* Eight senior officials arrested or being investigated
* Scepticism remains over Communist Party's commitment to crackdown
By John Ruwitch
SHANGHAI, Sept 13 (Reuters) - Behind China's aggressive drive to root out corruption is Wang Qishan, a historian-turned-economist who once felt so bad about getting free parking that he reportedly sent a colleague back to pay the fee.
President Xi Jinping launched the anti-corruption campaign after becoming Communist Party chief in November.
So far the party has announced the investigation or arrest of eight senior officials, including three from the 376-member elite Central Committee. Among them, former executives from oil giant PetroChina are being investigated in what appears to be the biggest graft probe into a state-run firm in years.
Wang, 65, heads the Central Commission for Discipline Inspection and ranks sixth in the party hierarchy. His power far exceeds this, said Cheng Li, a fellow at the Brookings Institution in Washington and an expert on Chinese politics.
"I would say that Wang Qishan is the second most powerful person next only to Xi Jinping," he said.
Given the secretive nature of China's Communist Party, there are few details on what Wang has done as its top graft-buster, a role he assumed when Xi became party chief.
Wang keeps a low profile and his public appearances and comments, like those of all top Chinese leaders, are usually scripted. He rarely gives interviews.
But observers said the fingerprints of the urbane former banker were visible in the anti-corruption campaign and in related efforts to force officials to behave less extravagantly.
"He is the lead actor in this," said Zhang Ming, a professor at Renmin University in Beijing.
IMMUNITY FOR ELITE REMOVED
For example, it was Wang who proposed the party scrap a decades-old unwritten rule that exempted incumbent and retired members of the seven-man Politburo Standing Committee, of which he belongs, from investigation for corruption, a source with direct knowledge of the matter said.
That landmark move was approved earlier this year by the Standing Committee, China's top political decision-making body, sources who have ties to the leadership or direct knowledge of the matter have told Reuters.
Wang has also reorganised parts of the discipline inspection commission and added two offices so the body can deepen its investigations into provincial leaders.
And one of the earliest initiatives Xi unveiled was a set of guidelines for officials that aimed to cut bureaucracy and formality.
"This came from the discipline commission," said Li of the Brookings Institution.
"He and Xi Jinping have a very, very good partnership."
To be sure, China has announced corruption crackdowns before that have met with little success. Experts say only deep and difficult political reforms will move the needle.
"If the anti-graft campaign is sustained and expanded, it could begin to challenge the party's systemic problems with corruption, but it's far too early to say that the government is committed to that," said Duncan Innes-Ker, senior China analyst at the Economist Intelligence Unit.
Like his predecessors, Xi says corruption threatens the party's very survival. He has said he wants to show he is serious by going after "tigers", or political heavyweights, not just "flies".
Some questioned the wisdom of moving Wang away from his role as a leading economic policymaker. A protege of former premier and economic reformer Zhu Rongji, he was even viewed as a dark-horse candidate for premier before the new leadership lineup was announced in November.
Now that the Chinese economy is showing signs of stability, the decision to deploy a man widely known as "the chief firefighter" to the corruption front might be a good call.
"They needed a person to deal with corruption who was strong and whose image and reputation were good, and he was that person. There was no one else they could have picked," said Jin Zhong, editor of Hong Kong's Open magazine, which follows elite Chinese politics.
Wang is under no illusions as to task ahead. Graft oils the wheels of government at almost every level in China, which ranked 80th out of 176 countries and territories on Transparency International's corruption perceptions index, where a higher ranking means a cleaner public sector.
"The war against corruption needs to be resolute and long-lasting, and it must be a battle to the death," the Xinhua news agency quoted Wang as saying in March.
Not everything has gone according to plan.
State media reported last week that Yu Qiyi, a 42-year-old engineer in the eastern city of Wenzhou, drowned after being repeatedly dunked in cold water while being interrogated by corruption investigators. Six officials will soon stand trial.
NO TIME FOR NONSENSE
Wang made a name for himself in the late 1990s when he sorted out a debt crisis in booming southern Guangdong province.
He then ran the island province of Hainan as governor before moving to Beijing where he tackled the deadly SARS pandemic in 2003 as mayor after his predecessor was sacked for covering it up.
His most recent job was vice premier with responsibility for the economy.
As an undergraduate in the mid-1970s he studied history in Shaanxi province, where he had worked on a farm at the height of the Cultural Revolution. In the 1980s Wang moved to Beijing and focused on rural policy, the forefront of China's market reforms. He later transitioned into banking.
Wang is a straight shooter, sources say. When being briefed by officials he has a habit of stopping them from reading from prepared statements and asking them questions.
"He does not have time for nonsense and demands direct answers," a source with ties to the leadership told Reuters.
The new administration has taken steps to introduce more transparency and adhere more closely to the rule of law in anti-corruption work, said Zhu Jiangnan, a professor at the University of Hong Kong who has researched corruption in China.
The discipline commission held its first news conference ever in January and launched a new website at the start of this month.
"I suspect some of those ideas are coming from Wang Qishan," Zhu said.
In May, Wang ordered disciplinary and supervisory cadres to give up club membership and VIP cards, apparently common gifts for officials, calling them "small objects (that) reflect a big problem in working style".
The son-in-law of late vice premier Yao Yilin, Wang has a reputation for modesty and honesty.
In a late August cover story, the influential state-run magazine, Southern People Weekly, recounted an incident in which a parking attendant insisted on letting Wang, then mayor of Beijing, park for free.
"The car behind started to get impatient and honk so Wang had to drive away," it said. Wang later sent a staffer to pay the fee. (Additional reporting by Benjamin Kang Lim and Ben Blanchard in BEIJING. Editing by Dean Yates)