Foreign investors hold lingering concerns about Australia's household debt levels and a potential housing bubble.

According to the Sydney Morning Herald, local economists and bankers are routinely asked by overseas investors about Australia's household debt levels.

Nearly 30% of funding for Australian banks comes from global markets. Should investors grow worried about personal debt levels in Australia, credit could tighten in the country.

Figures from the RBA reveal that total outstanding mortgage debt in Australia was approximately $1.1 trillion in April, while personal debt was about $141bn.

"Australia's reliance on wholesale markets and offshore elements needs to be taken into account because you are more exposed to how other markets perceive the relative risks of Australia to other alternatives," Standard & Poor's managing director rating services Fabienne Michaux told the SMH.

On a visit to Sydney in June, US-based investment fund GMO founder Jeremy Grantham, indicated that he thought rising interest rates would inevitably pop an Australian housing bubble.