China's defense ministry says it has opened an investigation into the country's highest-ranking general over grave violations of discipline and the law. The ministry gave no further details about accusations against General Zhang Youxia, who has widely been seen as President Xi Jinping's closest military ally. However, in China, the accusation of wrongdoing is usually a euphemism for corruption.

In its announcement, the ministry said another senior military officer, General Liu Zhenli, was also under investigation. Their removal follows the expulsion of nine top generals in October - one of the largest public crackdowns on the military in decades.

Zhang, 75, is a vice-chairman of the Central Military Commission (CMC) - the Communist Party group headed by President Xi which controls the armed forces. Zhang also sits on the party's top decision-making body, the 24-person Politburo. His father was one of the founding generals of the Chinese Communist Party and Zhang joined the army in 1968, holding significant combat experience.

Recent rumors regarding Zhang and Liu's potential investigation surfaced after they were absent from a high-level party event in December. This investigation coincides with President Xi's ongoing anti-corruption campaign targeting various government sectors, highlighting the military's vulnerability to scrutiny, which Xi views as a serious threat to the Communist Party.

Since Xi took office, the anti-corruption drives have intensified, particularly focusing on the military, with advocates noting it promotes good governance while critics suggest it has become a means to eliminate political rivals. The inquiry into Zhang and Liu has reduced the CMC membership from seven to two: Xi and Zhang Shengmin, who oversees the military's disciplinary matters.