China has charged 36 members of a "mafia-style" gang led by a tycoon who once launched a billion-dollar bid for an Australian mining firm, state media said.
A court had started prosecuting members of the gang, based in the southwestern province of Sichuan, including head of private company Hanlong group Liu Han and his brother Liu Wei, the official Xinhua news agency said.
Hanlong is a diversified firm with interests ranging from tourism to minerals and assets of more than 20 billion yuan ($A3.56 billion), it has said previously.
It launched a takeover bid of more than $A1.11 billion for listed Australian iron ore company Sundance Resources in 2011, but the deal collapsed in 2013 after Hanlong failed to follow through. Chinese media reports said at the time Liu Han had been detained.
"His business empire was backed by menace," Xinhua said in a lengthy report about the case.
"He and his gang have accumulated enormous wealth in property, mining, and electricity, through loan sharking and stockmarket manipulation, by illegal mergers and acquisitions and any other means available to them," it said, adding Liu's "criminal empire" had assets of 40 billion yuan.
Sichuan is one of the powerbases of Zhou Yongkang, China's former hugely powerful security chief who is at the centre of mounting speculation about his fate.
Authorities said this week that a former close aide of his, Ji Wenlin, most recently a vice-governor of the southern province of Hainan, was being investigated for "severe violations" of discipline and law in the latest sign of moves against Zhou, who retired in 2012.
State media hinted that Liu Han's gang had political connections to central government officials.
"Liu has reportedly even bribed his way to Beijing," the China Daily newspaper said in an editorial on Friday.
"But who extended umbrellas of protection for him? This is a bigger question than that (of) the outcome of ongoing court proceedings."
The influential Caixin magazine said Liu Han once had dealings with a businessman believed to be Zhou Yongkang's son.
Chinese President Xi Jinping has launched a much-publicised drive to crack down on corruption, vowing to take on senior "tigers" and low-level "flies".
No trial date for the gang has been announced.
