A man claiming to have worked as a secret Chinese operative for five years says Beijing has directed overseas assassinations, including on Australian soil.

Key points: Wang Liqiang is reported to be in an undisclosed Sydney location on a tourist visa

Wang Liqiang is reported to be in an undisclosed Sydney location on a tourist visa He has provided new information about the kidnapping of five booksellers from Hong Kong and their rendition to mainland China, according to Nine Newspapers

He has provided new information about the kidnapping of five booksellers from Hong Kong and their rendition to mainland China, according to Nine Newspapers He has also reportedly revealed information about spies from Beijing infiltrating the Hong Kong democracy movement, Taiwan's elections and involvement in Australian affairs

Government sources have confirmed to the ABC Wang "William" Liqiang has detailed the sensational allegations as he seeks political asylum.

Nine Newspapers have reported Mr Wang is in hiding in Sydney after recently providing a sworn statement to Australia's domestic spy agency ASIO outlining Beijing's covert operations.

One senior official, speaking to the ABC on the condition of anonymity, said the challenge for security agencies was to now "separate fact from fiction" while assessing Mr Wang's disclosures.

The Treasurer said the Government is following up on the "sensitive matter". ( ABC News: Tamara Penniket )

In the statement Mr Wang provided ASIO last month, he reportedly states: "I have been personally involved and participated in a series of espionage activities".

According to Nine Newspapers, Mr Wang has provided new details about the kidnapping of five booksellers who specialised in works critical of Chinese leaders based in Hong Kong, starting in 2015, and their rendition to mainland China.

He is also reported to have said spies from Beijing were infiltrating Hong Kong's pro-democracy movement, influencing Taiwan's elections and "operating with impunity in Australia", according to The Sydney Morning Herald and The Age.

Treasurer Josh Frydenberg said it was a "sensitive matter" being followed up by the relevant authorities.

"These are very disturbing reports and the matter is now in the hands of the appropriate law enforcement agencies so I wouldn't comment on the particulars of individual cases," he said.

"The Government makes no apologies for the measures we have taken to ensure that we have foreign interference laws in place."

According to the reports, Mr Wang is seeking political asylum and remains in an undisclosed location in Sydney on a tourist visa.

Mr Wang told Nine Newspapers the Chinese Communist Party "infiltrates all countries in areas such as military, business and culture, in order to achieve its goal".

He continued: "You shouldn't underestimate our organisation … we were cultivated and trained by the organisation for many years before taking up important positions.

"[The Chinese Communist Party] wants to ensure no-one threatens its authority."

In a clip from 60 Minutes posted to social media on Saturday, Mr Wang said, through a translator, that he was "responsible for organising the cyber army to attack people online".

"Imagine the consequence of betraying the organisation."

When asked why he had decided to seek political asylum in Australia and detail his involvement in such covert operations, he said: "I know very well that the Chinese Communist Party can never be trusted. Once I go back, I will be dead."

Mr Wang reportedly said Xi Jinping's Chinese Community Party "can never be trusted". ( Xinhua/Ju Peng: AP )

When asked about reports Mr Wang is currently in Sydney and seeking asylum, Opposition Leader Anthony Albanese said: "These reports are of real concern."

He called for "Australia's national sovereignty [to be] protected," adding, "we will await processes with the Government and one of the things that we will be seeking next week is a briefing from the appropriate authorities on these issues".

The Labor leader said the question of whether the country should accept Mr Wang's reported asylum request would be "a decision for the Government".

"But, I'm sympathetic with the circumstances and we know that he has outlined a range of activities which clearly put him in a circumstance whereby it's a legitimate claim for asylum," Mr Albanese added.

Responding to the news of Mr Wang's reported asylum claim on Twitter, former Chinese diplomat Chen Yonglin said Mr Wang would not be safe in Australia.

"He'd better move to America later. He is not safe in Australia. Since he revealed names and IDs of operatives and kidnappings, he may be executed," he wrote.

"Extremely difficult to hide the whole family from a powerful surveillance state like China in [a] modern high-tech world.

"China collects all data of WeChat users, listens to Apple [mobile phones] and hacks PCs, besides [there are] over 1,000 operatives on the payroll," he added.