China’s military leadership is in turmoil after its most senior general – a close ally of Xi Jinping – was placed under investigation for “suspected serious violations of discipline and law”.

Zhang Youxia is the joint vice-chairperson of the Central Military Commission (CMC), the ruling body of China’s People’s Liberation Army (PLA). Second only to Xi in the military command structure, Zhang has long been seen as the Chinese president’s closest military ally.

The defence ministry announced on Saturday that Zhang and Liu Zhenli, chief of staff of the CMC’s joint staff department, were under investigation.

An editorial published in the army newspaper Liberation Army Daily on Sunday said that Zhang and Liu “seriously betrayed the trust and expectations” of the Communist party and the CMC, and “fostered political and corruption problems that undermined the party’s absolute leadership over the military and threatened the party’s ruling foundation”.

The Wall Street Journal reported that Zhang was accused of leaking information about the country’s nuclear weapons programme to the US and accepting bribes for official acts, including the promotion of an officer to defence minister, citing people familiar with a high-level briefing on the allegations.

Zhang is also a member of the elite politburo of the ruling Communist party and is one of just a few leading officers with combat experience. Aged 75, Zhang was retained in the military leadership by Xi past the normal age of retirement, indicating a high level of trust in the general that he has now purged.

The military was one of the main targets of a broad corruption crackdown ordered by Xi in 2012. That drive reached the upper echelons of the PLA in 2023 when the elite Rocket Force was targeted.