SYDNEY - China's alleged attempts to spy on Australia and even plant a Beijing-backed MP in Parliament have prompted calls for tighter laws to combat foreign interference, including security screening incoming MPs.

In recent weeks, the three most recent Australian former prime ministers, Malcolm Turnbull, Tony Abbott, and Kevin Rudd, have all called for greater vigilance to prevent meddling by China in domestic affairs.

Mr Rudd said Australia needed to protect against China's efforts to "create a more favourable environment for itself". But he warned against overreacting or becoming excessively paranoid.

"I don't think we can be naive about this," he told ABC News, and added, using slang to refer to communist infiltration, "But at the same time, it's kind of crazy to overreact and to get into reds under the bed land."

Mr Abbott also said he supported efforts to curb Chinese interference, but noted this must not descend into questioning the loyalties of the Chinese-Australian community.

"It's right… that officialdom, including our security agencies, is now highly focused on Chinese influence-peddling at every level, from undergraduates to the senior reaches of business, to Parliament itself," he told The Lowy Institute. "This will need deft handling, though."

Australia has already introduced some of the world's toughest measures to combat foreign interference, including bans on foreign donations and a compulsory registry of all lobbyists representing foreign entities.

Earlier this week, Prime Minister Scott Morrison announced a new A$88 million task force to detect and disrupt nefarious foreign elements. It will be led by Australia's domestic spy agency, the Australian Security Intelligence Organisation.

Mr Morrison said he is regularly asked by foreign counterparts about Australia's efforts to combat interference.

"One of the key issues that other leaders raise with me is how Australia has been able to move so successfully in both identifying, calling out and taking action to counter foreign interference," he told reporters.

But there have been calls for tougher measures.

Labor has proposed a new law to force political parties to disclose donations within seven days. Currently, disclosures are typically not released for months after they were made and long after election campaigns are over.

Former foreign minister Julie Bishop warned that foreign interference could erode the public's faith in the integrity of elections and democratic processes. She voiced support for more timely disclosure of donations as well as for potentially subjecting MPs to security screening.

"I always found it extraordinary that I as foreign minister had no need for a security clearance," she told The Centre for Independent Studies. "My staff had to go through the most rigorous security clearances. But no politician is ever subjected to that."

In recent months, claims of alleged interference have implicated both the ruling Liberal-National coalition and the Labor opposition party.

The most recent allegations involve a Melbourne businessman, Mr Nick Zhao, 31, who told ASIO he was offered A$1 million to run as a Liberal MP by a Chinese national with alleged links to the Communist Party. Zhao was found dead in a hotel room in March. His death is being investigated by the coroner. According to The Australian newspaper, which cited several unnamed sources, Victorian police do not regard the death as suspicious.

Separately, a Chinese man claiming to be a defecting Chinese spy, Mr Wang Liqiang, gave an interview with The Age in which he claimed to have been involved in operations to interfere with elections in Taiwan and to kidnap critics of the Communist Party in Hong Kong. Mr Wang, 27, who is seeking asylum in Australia, also claimed to have information about efforts by Chinese intelligence to fund and conduct interference operations in Australian politics. He has made a statement to ASIO, which is investigating his claims.

But some of those have come under question.

Two researchers, Mr Adam Ni and Ms Yun Jiang, said Mr Wang's claims were unconvincing and many of his allegations were unsupported, based on the available evidence.

"It is highly unusual for one junior intelligence operative… to play a big role in all these high-profile operations in different jurisdictions in a short period of time," they wrote in the online China Neican newsletter about China-related issues.

Others, including Ms Bishop, noted that it was unusual for a defecting spy to give media interviews.

Australian authorities are investigating his authenticity and have been urged to publicly reveal their findings. Either way, Australia's authorities have repeatedly made it clear that they regard foreign interference as a serious and growing threat.

The director-general of the Office of National Intelligence, Mr Nick Warner, told a parliamentary hearing last week that he agreed with a former ASIO chief that the threat was at "unprecedentedly high levels".