Most suburbs recorded weaker auction results in the final month of winter. (ABC News: John Gunn)
Property data firm Cotality has released its monthly national Home Value Index (HVI) showing a 0.9 per cent fall in August.
This marks the fifth straight month that Australian property prices have slipped.
The data also shows the nation's housing downturn has accelerated, as most suburbs recorded weaker auction results in the final month of winter.
The country's median property value is now 3.6 per cent below the record high recorded in March.
Sydney continued to lead the pace of declines, with home values down 1.4 per cent in August to be 7.1 per cent below peak levels recorded in February.
Prices in Melbourne and Canberra both fell 1.1 per cent, while Brisbane dropped 1 per cent.
The other mid-sized capitals were not far behind, with Adelaide and Perth home values dropping 0.8 per cent in August.
House prices in the capital cities continue to fall. (Supplied: Cotality)
Independent economist Alan Oster pointed to some large geographical differences across the national housing market.
"If you go to Perth, they're still going at an annualised rate of 20 per cent," Mr Oster said.
"If you're in Sydney and Melbourne, they're sort of going backwards at around 7 to 8 per cent.
"I suspect those sorts of trends will continue for a while."
New Cotality modelling data shows what property prices could look like across the capitals if the market falls by 5, 10, 15 or 20 per cent.
The national property market has been hit by several headwinds in recent months, including three Reserve Bank interest rate hikes, and the federal government's decision to restrict negative gearing and increase capital gains tax.
