The Chinese Communist Party's expulsion of a former top aide to ex-president Hu Jintao for corruption is a political move reinforcing Xi Jinping's power, analysts said Tuesday.

Following an internal Party investigation Ling Jihua, once one of Hu's most senior advisers, was expelled and handed over to prosecutors who formally arrested him, authorities said Monday.

The development came three years after his son was killed in a Ferrari crash that also injured two female passengers, one of them naked, a scandal that triggered his downfall.

Ling, 58, will almost certainly face trial, with a guilty sentence and jail term effectively guaranteed to follow.

Since coming to power Xi has overseen a high-profile crackdown on graft that has deposed several senior officials, but in the absence of systemic reforms critics say the drive is open to being used for political faction-fighting.

The campaign also risks re-inforcing perceptions of widespread corruption in the ruling organisation.

Previous scalps include former security chief Zhou Yongkang, who was jailed for life earlier this year, and Xu Caihou, once China's second most senior military officer, who died of cancer earlier this year while under investigation.

Joseph Cheng, professor of political science at City University of Hong Kong, said Ling's targeting suggested President Xi was confident of taking on high-profile cadres associated with his predecessors.

Retired leaders in China are seen as continuing to wield influence behind the scenes, including regarding their allies, and Zhou has links to former Chinese president Jiang Zemin.

"By prosecuting figures formerly associated with first Jiang Zemin, and then Hu Jintao, certainly means that Xi Jinping wants to demonstrate his determination to get rid of all resistance to his policy programme irrespective of their affiliations and associations," Cheng told AFP.

"It certainly generates pressure on previous leaders including Jiang Zemin and Hu Jintao," he said.

Hong Kong and Taiwan-based media have speculated that Ling -- along with Zhou, Xu, and former party rising star Bo Xilai, who was jailed in 2013 after a murder and graft investigation -- had formed a political faction opposed to Xi.

The alleged cabal has been dubbed the "New Gang of Four", a reference to the infamous quartet including Mao Zedong's widow who were put on trial in 1980.

"The Communist Party of China (CPC) has moved a major step forward in its anti-graft campaign," state news agency Xinhua declared in a triumphant commentary. "Like water and fire, the CPC doesn't tolerate corruption."

The commentary indicated that Ling had engaged in internal plotting, saying that his case "served as a warning that it's absolutely forbidden to organise factions within the Party".

- 'Too close to the sun' -

Ling had become an embarrassment to the ruling party, said Kerry Brown, professor of Chinese politics at the University of Sydney, pointing out that the Ferrari crash in Beijing came at a sensitive time during the power transition between Hu and Xi.

"Ling was simply unable to rein in people around him cashing in on his political links - the most obvious being his son who was evidently out of control," he said.

"Ling harmed the Party, in this story, just like Zhou did, and the Party has taken its revenge."

He described the expulsion as "the final despatching of someone who flew too close to the sun after rising from a very modest background".

"It just goes to prove that there is no more dangerous or treacherous place in the world to try to exist in than the upper reaches of Chinese politics," he told AFP.

State-run media made no mention of Ling's links to Hu, and only passing reference to allegations against his family.

In an editorial the Global Times, which is affiliated with the Communist mouthpiece People's Daily, said Ling's "close relatives indulged in their desires and became involved in criminal behaviour and they paid a high price".

In June 2014 the party announced an investigation into his brother Ling Zhengce for "serious discipline violations". Ling was a vice-president of the Chinese People's Political Consultative Conference, a Communist-controlled debating chamber, in the family's home province of Shanxi.

Xinhua on Monday also implicated Ling's wife, while reports last year said that his brother-in-law had been held.

The People's Daily, the official Communist Party mouthpiece said Ling's case should serve as a lesson to other officials.

"Strict political discipline and rules will resolutely overcome organisational and discipline problems, (so) we can protect the party's structure," it said.

Party disciplinary officials opened an investigation into Ling for "suspected serious disciplinary violations" -- normally a euphemism for corruption -- in December.