Australian Federal Police have restrained the goods and property in Melbourne, Sydney and the Gold Coast, as part of a probe into offshore funds allegedly being laundered in Australia.

The investigation comes after the Chinese Ministry of Public Security requested AFP help in 2016 to identify possible Chinese nationals involved in the illegal scheme.

It's alleged two Chinese nationals travelled to Australia in 2015 to establish shell companies, so they could use money raised in China through defrauding investors to buy residential and development property in Australia.

Investigators raided properties in the Melbourne CBD and suburbs of Lower Plenty and Hawthorn, and in the Sydney suburb of Waterloo on Wednesday and Thursday, seizing properties, vehicles and luxury items.

Police say investigations into individuals involved are ongoing.

AFP Commander Bruce Hill said the probe highlighted the importance of international collaboration to stop money laundering and its harmful impact on the Australian community.

"This kind of activity - where significant criminal proceeds are moved into Australian assets - can erode the level playing field for Australian homebuyers and small business owners. This ripple effect impacts our whole community. It is far from a victimless crime," he said.

"Our message to people thinking about laundering proceeds of crime in Australia is clear: your money and assets are not hidden from the AFP and our international partners. We will catch you."

The $8.5 million in restrained assets are now subject to a Commonwealth restraining order.

It is the third separate investigation since October last year, involving Chinese nationals allegedly creating shell companies, laundering money and evading tax.

In October 2018, the AFP restrained three homes and two bank accounts relating to proceeds of crime with an estimated value of $2 million.

Australian Associated Press