Price growth appears to be gradually slowing, according to new research from RP Data-Rismark.

The property research house found national median prices increased 0.6% in May, to be up 12.1% over the past year.

The only city that has remained buoyant is Melbourne - prices rose 1.5% in May to be up an impressive 18.2% over the year. By comparison, Sydney prices only rose 1.5% in May and 11.3% over the past year.

Brisbane experienced a short decline in April, but prices bounced back in May, rising 1.4%, while Adelaide prices rose a modest 0.5%. Perth prices declined by 2.4%.

According to the ANZ Economic Update, the double digit growth in house prices that the country experienced last year in most capital cities was "clearly unsustainable" as housing affordability deteriorates, mortgage rates rise and the first home buyer grants are phased out.

ANZ also reported that housing credit expanded 0.7% in May to be 8.8% higher over the year, as a result of gains in both owner occupier and investor segments.