The disappearance of Chinese Defence Minister Li Shangfu highlights the opaque and complex nature of the People's Liberation Army (PLA). In the Chinese system, the Minister of National Defence is seen as significantly less powerful than the U.S. defence secretary and many international equivalents.

The disappearance of Chinese Defence Minister Li Shangfu highlights the opaque and complex nature of the People's Liberation Army (PLA), diplomats and analysts say.

Pressmen gathered on Friday that Li is under investigation over the corrupt procurement of military equipment during his previous role. Eight other senior officials are also being investigated. His fate has not been officially explained.

In the Chinese system, the Minister of National Defence is seen as significantly less powerful than the U.S. defence secretary and many international equivalents.

The position is essentially a diplomatic and ceremonial role without a direct command function.

Even so, Li is among the six military officials under Commander-in-Chief and President Xi Jinping on the core Central Military Commission (CMC) and is one of five State Councillors, a post outranking a regular cabinet minister.

An aerospace engineer who worked in China's satellite program, Li was seen as technocrat who helped implement Xi's modernisation vision for the PLA, military attaches and analysts say.

The PLA is the armed wing of the ruling Communist Party and, according the Pentagon's annual report on China's military, "does not directly serve the state but is rather under the direct control of the party".

As Li rose through his career to this point, he would have been vetted to ensure he was absolutely loyal to the party and to Xi.

The PLA still operates an active cadre of political commissars who flank the command chain, tasked with ensuring loyalty, unity and morale. The commissar system does not have clear equivalents outside traditional Communist militaries.