"He is a very bad man," says Melbourne's Zheng Jiefu, who says his family and business had been threatened by the flamboyant billionaire. "He did damage to my business and damage to my family".

While some social media users on Wednesday labelled Guo Wengui, aka Miles Kwok, as "China's Julian Assange", after his live internet broadcast in which he made corruption allegations against senior political figures, Mr Zheng says he knows a darker truth.

Mr Zheng claims Mr Guo sent thugs to Brighton to follow him around in a Mitsubishi four-wheel drive, and stuffed threatening letters in his mailbox two years ago.

"That was Mr Guo."

"I am very happy Interpol has issued this notice," Mr Zheng said by phone.

Mr Guo has been living in luxurious exile in New York and London, profiling his lifestyle on Twitter, and last month it emerged he was a member of Donald Trump's Mar-a-lago resort in Florida. He has appeared in three sensational video interviews, broadcast online, in which he has levelled corruption allegations at the family of Chinese vice ministers.

Mr Guo has also admitted toppling a former Beijing deputy mayor by providing a sex tape to police.

Hours before the latest webcast, recorded by Voice of America in New York, went to air on Wednesday, Interpol issued a red notice for his arrest pending extradition. China's Foreign Ministry labelled him a criminal suspect.

Amnesty International has said the red notice against Mr Guo's raises questions about the political interference of China in Interpol, whose president is former Chinese vice minister of public security Meng Hongwei.

But Mr Zheng believes Mr Guo is a central figure in one of China's "black societies".

The property developer says he has been providing information about Mr Guo to Chinese authorities for the past four years. "I told the Chinese government everything," he said.

If his safety concerns are overcome, Mr Zheng says he may return to China in the near future to give evidence. His fear in returning to China is Mr Guo's black society, not the Chinese police, he says.

Mr Zheng has assets worth about $40 million in Australia. But in China, he had controlled a $2billion conglomerate, Tianjin Bohai Circle, until it was appropriated by Mr Guo and China's then powerful spymaster Ma Jian.

Mr Guo is wanted by Interpol for allegedly bribing former Chinese state security vice-minister Ma Jian with 60 million yuan ($11.5 million). Ma is under investigation for corruption.

Mr Zheng told Fairfax Media in 2015 that Mr Guo and Mr Ma heavied all of his important relationships, destroyed his marriage, threatened his children and, at one stage, turned up with six Reservoir Dogs-style henchmen in sunglasses and black coats.

Mr Guo left China two years ago after his assets of $US17 billion ($22.6 million) were frozen in a corruption investigation into Mr Ma.

Mr Guo has claimed that the red notice was issued to put pressure on Voice of America not to broadcast Mr Guo's interview.

The interview went ahead, although Mr Guo complained it was cut short after one hour. VOA has said it will broadcast more of the material it recorded after fact-checking.

Another video, appearing to show Mr Ma confessing to how Mr Guo bribed him, was circulating online Chinese sites on Wednesday, in apparent retaliation to the tycoon's claims.

In it, Mr Ma says he helped Mr Guo harass his business opponents in return for 60 million yuan in bribes, which included borrowing 6 million yuan to purchase six apartments and 20 million yuan to buy 10 offices, as well as 3 million yuan in "red envelopes" and 200,000 Hong Kong dollars worth of shoes and suits. Financial news website Caixin published the video.

The duelling video claims of corruption are being read as a proxy war between China's elite political factions ahead of an important meeting in November which will determine the transfer of power in the Communist Party's Politburo for the next five years.

- with Sanghee Liu