Sydney house rental prices have surged to a record high, while in Melbourne they remain at highest-ever levels.
Median weekly house rents in Sydney hit a fresh record of $530 and unit rents lifted to $500 in the June quarter, according to the latest Domain Group Rental Report, released Thursday.
In Melbourne, house rents remained at a record of $390 a week - a 2.6 per cent lift over the year to June - with unit rents jumping to $370.
Brisbane, Adelaide, Hobart and Canberra house rents were flat over the same period, while those in Perth and Darwin fell.
Despite few signs of prices cooling in the rental market, Domain senior economist Andrew Wilson said vacancy rates were improving in some capitals.
The June national capital city vacancy rate was 2.2 per cent for houses, up from 2.0 per cent the previous three months.
"The data indicates that increased investor activity and construction may be offsetting the rising demand for rental properties," Dr Wilson said.
"The demand is driven by solid migration levels and low first home buyer numbers."
Rental yields for investors - the rate of income compared to a property's value - were steady in Sydney, but remain the lowest compared to other Australian capitals.
Dr Wilson said residential returns were continuing to drive property investment but noted that "relief may be on the way for tenants".
"On average, investors are seeing positive returns," he said.
"Residential yields remain ahead of average term deposit rates, which are currently at historically low levels."
The latest housing data comes after figures from Australia's largest mortgage broker earlier this week showed the number of property investor loans fell in June.
AFG processed a record 11,056 mortgages worth $5.1 billion in June, but only 36.9 per cent were for property investment, down from 40.9 per cent in May.