Bo Xilai, the recently disgraced Communist Party boss who was once one of China's most popular leaders, may not be the only top Chinese leader headed for a fall.

Speculation is rife throughout Western media and overseas Chinese news sources on the possibility that Zhou Yongkang, a member of China's Politburo Standing Committee, the group of nine most powerful politicians and de facto oligarchy of the country, may be investigated for connections with and support given to Bo.

Bo was removed as leader of the Chongqing municipal zone in late March and from top party posts in early April. His wife, Gu Kailai, is being investigated as a prime suspect in the murder of British businessman Neil Heywood. Bo's former confidant, Wang Lijun, who once served as Chongqing chief of police and deputy mayor, is suspected of having attempted to defect to the U.S. in February and may have provided details of Bo and Gu's illegal practices to U.S. diplomats and later to Chinese authorities.

The South China Morning Post, a major English-language newspaper in Hong Kong, reported citing anonymous sources that a government investigative task force arrived in Hong Kong on Monday to look into Bo's supposedly large assets there.

Chinese official media however, has been absolutely silent on whether Zhou, the secretary of the Chinese Communist Party Central Committee's Political and Legislative Affairs Committee, is being investigated as well. 

The innocuously named Political and Legislative Affairs Committee in fact oversees the enforcement of all legal issues in China, effectively making it a powerful party organ that ultimately controls the police and public security forces.

Zhou has been described in the West as having been the only official to argue against Bo's suspension from the 25-member Politburo. Whether that truly made him a target of Bo's political enemies remains to be seen.

If anything, Zhou's recent activities have been spotlighted by official Chinese media. On Tuesday, an essay of his on political and legal developments in China was published in People's Daily, the official mouthpiece of the Central Committee, indicating that he is still an influent member of the elite. Still, some Western observers suspect that Zhou may be increasingly scrutinized for his close connections to Bo Xilai.

But even if Zhou is implicated in anything serious, further expansion of the scandal and political purge surrounding Bo may be unlikely as China moves to reassure its own public and the international community. This may be especially important to the country's leaders as they focus on preparing for a stable political transition in late 2012, when a new president and premier are expected.

By that time Zhou will be leaving office regardless of his connections with Bo. Seven members of the nine-member Politburo Standing Committee, including Zhou, will be resigning their positions and will likely be replaced by a younger generation of politicians with very different backgrounds and policy priorities. 

Cheng Li, the Director of Research and a Senior Fellow of the John L. Thornton China Center at the Brookings Institution, a major D.C. think tank, wrote in the Washington Quarterly in early 2012 that Meng Jianzhu, China's minister of public security, seems to be an ideal candidate to succeed his boss Zhou Yongkang on the Politburo Standing Committee.