BEIJING – Communist Party authorities are investigating a vice minister of public security, part of a widening anti-corruption campaign that could ensnare higher leaders and reverberate across the party’s top ranks.

Vice Minister Li Dongsheng is the latest official with close ties to China’s powerful former security czar Zhou Yongkang to be targeted. For months, rumors have swirled of a politically explosive move to take down Zhou. All the while, a series of government officials and oil executives whose careers can be linked to Zhou have been methodically taken down.

The terse one-sentence announcement of the party’s investigation into Li was one of its most significant to date.

It was posted Friday night on the website of the agency in the Communist Party that investigates corrupt party cadres.

Within the public security ministry, Li is vice head of the office in charge of crackdowns on the Falun Gong spiritual movement in China. He is one of the roughly 350 elite leaders on the party’s Central Committee.

Li, 58, was appointed to the position in 2009, during Zhou’s tenure as a powerful member of the Standing Committee, the party’s highest ruling body. If Zhou is the ultimate target of such investigations, then party leaders, including President Xi Jinping, would be breaking an unwritten party rule against going after current or former Standing Committee members.

Reviled by many as head of China’s police and authoritarian forces, Zhou built the domestic security system into a feared, sprawling apparatus. During his tenure as head of the Ministry of Public Security, then as overseer of its police, courts and intelligence work, spending on domestic security surpassed even the defense budget.