Australian real estate in being sold and marketed exclusively to foreign investors with local buyers not even aware the properties in question are up for sale.

More than 100 real estate firms have showed up in Mainland China, exclusively selling Australian properties directly to Chinese investors, bypassing Australian buyers, according to reports in The Australian.

At the upper end of the housing market, prestige Sydney property agency Simeon Manners – which says it has sold more than $100 million of Sydney property to “China’s most astute buyers and investors” – operates a sales site that cannot be accessed from within Australia.

Director Mark Manners said many of the listings on the site, sydneyluxuryproperty.com, could only be accessed from a foreign IP address and were private or off-market listings placed on behalf of owners who wanted a discreet sale to a foreign purchaser.

Simeon Manners is just one of a number of firm offering Australian fixed housing to foreign buyers, according to reports in The Australian.

Under foreign investment Review Board restrictions, the agents are not breaking the law but the buyers potentially are.

Adelaide firm DG Real Estate’s Simon Hou said his firm sold many properties – including a $4.2million mansion in the upmarket suburb of Unley – to wealthy Chinese investors and had not had FIRB reject an approval in recent years.

It is estimated that Chinese investors spent more than $5.9 billion on Australian real estate last year, in a market worth $270bn.

The head of China-based online property portal juwai.com, Andrew Taylor, told The Australian newspaper developers “who have been marketing properties exclusively in China and Asia for years”.

“There are vendors who don’t really want to put their home on the market but have a magic number that they would be willing to sell at (who) often put their homes online without listing them in Australia,” he said.

“That way they have exposure to the Chinese buyers without having to put up a sign board and do open-for-inspections.”