Former top general Guo Boxiong has confessed to corruption and is set to face graft charges, the Chinese authorities announced yesterday.

This sets the scene for the most high-profile anti-corruption case in the history of the People's Liberation Army (PLA), which comes amid sweeping military reforms implemented by President Xi Jinping.

Gen Guo, 73, was found to have taken advantage of his position to seek promotions and benefits for others, investigators said in a statement. He took "huge bribes" personally and through his family.

The news comes eight months after Gen Guo, once one of the PLA's most powerful men, was sacked from the Communist Party.

His case follows that of Gen Xu Caihou, a fellow Central Military Commission (CMC) vice-chairman, who had earlier confessed to taking large bribes following a graft investigation. But Gen Xu, 72, died of bladder cancer in March last year before he could face charges.

There had been speculation investigators might thus take more care when interrogating Gen Guo, who is also suffering from cancer. The eight months taken from his sacking to the end of the probe is double the four months taken for Gen Xu.

But Beijing-based military analyst Song Zhongping feels that a more likely reason for the delay is their different portfolios.

"Guo handled operations, which include training and equipment purchases. These matters are more complex and require more time to investigate than personnel affairs, which Xu was in charge of," he said.

Shanghai-based military expert Ni Lexiong said that Gen Xu's death would have complicated investigations into Gen Guo's case too.

"As the top military leaders, there would have been matters that perhaps only the two of them knew," he told The Straits Times. "With Xu's death, it would be harder to corroborate certain things, and he could even lay blame on Xu."

Still, the probe has not taken longer because "it is best not to drag things out since military reforms are officially under way", he said.

Before their retirement, Gen Guo and Gen Xu served together under Mr Xi's predecessor Hu Jintao. Mr Xi was also a CMC vice-chairman with the men from 2010 to 2012.

There were no details released yesterday of Gen Guo's alleged corruption, although Hong Kong's South China Morning Post on Monday quoted an unnamed source as saying that he was expected to be charged with taking 80 million yuan (S$17 million) in bribes.

Investigators said family members and others implicated in Gen Guo's case would also be dealt with by the law. His son Guo Zhenggang, a major-general, was put under investigation in March last year.

An online PLA Daily commentary yesterday said Gen Guo, like Gen Xu, was a "greedy degenerate" who deserves to be punished.