Exclusive | Zhou Yongkang, former security tsar linked to Bo Xilai, faces corruption probe

Top Communist Party leaders have agreed to open a corruption investigation into former security tsar Zhou Yongkang, one of China's most powerful politicians in the past decade.

The move against Zhou - a retired member of the Politburo's all-powerful Standing Committee - could send even bigger political shockwaves through Beijing than the trial of Bo Xilai, who was widely considered a key Zhou ally.

Current and retired top leaders endorsed the decision earlier this month during the secretive annual party meeting at the resort of Beidaihe in Hebei province. According to sources familiar with the leadership's thinking, President Xi Jinping and his administration are determined to use the case to galvanise the anti-graft campaign.

No Politburo Standing Committee member - retired or sitting - has been investigated for economic crimes since the end of the Cultural Revolution nearly 40 years ago.

Sources said top leaders made the decision in view of the rising anger inside the party at the scale of the corruption problem and the vast fortune that Zhou's family has amassed. Xi ordered officials in charge of the case to "get to the bottom of it".

By investigating Zhou, who is one rank higher than Bo in the power structure, Xi would be seeking the biggest scalp in the party's campaign against graft.