Australia is investigating an alleged Chinese plot to infiltrate its federal parliament by turning a Chinese-Australian businessman into a political operative, the country's counter-espionage agency has said.

Nine network programme "60 Minutes" broadcast explosive allegations Sunday night that suspected Chinese operatives had offered Bo "Nick" Zhao AUD1 million (USD 679,000) to run as a candidate in a federal seat in Melbourne.

The 32-year-old luxury car dealer had reportedly disclosed the alleged approach for him to spy to the Australia Security Intelligence Organisation (ASIO) last year, before he was found dead in a motel room in March.

In a rare public statement late Sunday night, ASIO head Mike Burgess said the agency was "previously aware of the matters" and has been "actively investigating them".

Burgess said he would not comment further as Zhao's death was subject to an inquest.

"Hostile foreign intelligence activity continues to pose a real threat to our nation and its security," he added.

Police have been unable to determine how Zhao died.

Parliamentary intelligence committee chief Andrew Hastie described the alleged episode in Melbourne as "surreal" and "like something out of a spy novel".

"This isn't just cash in a bag, given for favours, this is a state-sponsored attempt to infiltrate our parliament using an Australian citizen and basically run them as an agent of foreign influence in our democratic system," he told 60 Minutes.

"So this is really significant and Australians should be very, very concerned about this." The claims come just days after a Chinese spy reportedly gave ASIO the identities of China's senior military intelligence officers in Hong Kong and provided details about how they funded and conducted operations in the city, Taiwan and Australia.

China has dismissed defector Wang "William" Liqiang as an unemployed fraudster and fugitive, but there are growing calls in Australia to grant him political asylum.

The revelations are likely to further heighten tensions between Beijing and Canberra. Recently retired ASIO head Duncan Lewis said last week that China wanted to "take over" Australia's political system with an "insidious" and systematic campaign of espionage and influence peddling.

China is also widely suspected of being behind major intrusions into the computer systems of Australia's parliament and a university with close ties to the government and security services.

But Beijing has previously angrily denied allegations it was covertly meddling in Australian affairs.