CHINA - On a day internationally dedicated to the preservation of tigers, China caught one of its biggest "tigers" - a term used by Chinese to refer to high-ranking corrupt officials.
Zhou Yongkang, former security chief, is being investigated for suspicion of "serious disciplinary violations", the Communist Party of China Central Committee announced on Tuesday, International Tiger Day.
He is the most senior-level official to be under official investigation since China's reform and opening-up began in 1978.
Zhou, 71, is a former member of the Standing Committee of the Political Bureau of the CPC Central Committee, the top Chinese leadership body.
Fighting corruption has been a top priority of the CPC Central Committee since November 2012, when the Party's new leadership was elected. President Xi Jinping told disciplinary officials early this year that they should fight corruption with firm resolution "like using strong medicine to cure a serious illness."
In January last year, Xi said that anti-graft authorities should go after both "flies" and "tigers" - meaning corrupt officials of both lower and senior levels.
A total of 38 "tigers" - senior officials of provincial level and above - have been probed since the CPC elected its new leadership.
Speculation over an investigation of Zhou grew early this year along with the fall of his former subordinates. Anti-graft authorities have announced probes of his former secretaries, most of them senior provincial-level officials.
Zhou's last public appearance was on Oct 1, when he attended the 60th anniversary of the China University of Petroleum, where he studied from 1961 to 1966.
On March 3, when Lyu Xinhua, spokesman for the Chinese People's Political Consultative Conference National Committee, was asked about Zhou's case, he said that the Party will have zero tolerance for corruption no matter how high the official.
"That's all I can answer, and you know what I mean," Lyu told reporters during the top political advisory body's annual session.
Li Chengyan, a professor of clean-governance research at Peking University, said that the probe of Zhou reflects the Party's firm resolution to fight corruption.
Power should be supervised in a more effective manner in line with the law, he added.
From 2007 to 2013, Zhou was secretary of the Commission for Political and Legal Affairs of the CPC Central Committee, the country's top security and judicial agency. Before that, he served as minister of public security from 2002 to 2007 and as Party secretary of Sichuan province from 1999 to 2002.
He worked in the oil industry from 1967 to 1998 and became general manager of China National Petroleum Corporation in 1996.
A report by Caixin magazine alleged that Zhou Bin, the son of Zhou Yongkang, had accumulated a huge amount of wealth with his father's influence in the gasoline industry. In one case, the younger Zhou bought an oilfield for less than 20 million yuan (S$4.03 million) from CNPC and sold it for 550 million yuan.
Ren Jianming, a professor of anti-graft studies at Beihang University, said that the fall of Zhou could convince the public that the Party's new leaders are serious in fighting corruption.