Caging top 'tiger' invites call for deeper reform

Lay foundation for rule of law

The news that Zhou Yongkang, until recently one of the most powerful men in China, is to be investigated for suspected "serious disciplinary violations" is the clearest indication yet of the top leader Xi Jinping's determination to tackle corruption by rooting out the "tigers as well as flies".

Until he retired in 2012, Zhou was the top security chief and a member of the Politburo Standing Committee. He is the most senior Chinese official to be investigated since the "Gang of Four" were brought to justice in the early 1980s.