Chinese officials are announcing that the country's powerful deputy minister of state security is being investigated as part of a broad government anti-corruption sweep.

The Central Commission of Disciplinary Inspection said on its website Friday that Ma Jian was suspected of serious disciplinary violations. It didn't provide more details, but that wording typically refers to investigations into corruption.

Ma headed the country's sprawling anti-espionage operation and was reportedly detained last week. His investigation follows the arrest and investigation of former Politburo Standing Committee member Zhou Yongkang, who oversaw internal security.