The Reserve Bank says foreign investors have helped to boost the housing supply, rather than make houses too expensive for locals, at a time when the economy needs it.

But it has admitted that foreigners have contributed ''somewhat'' to the rise in house prices, particularly for higher-priced dwellings.

High house prices: Foreign investors not to blame, says RBA. Credit:James Alcock

The RBA Bulletin for the June quarter has dedicated a chapter to ''foreign investment in residential real estate'' at a time when there are concerns over the high cost of housing. It comes a week after the International Monetary Fund warned that homes in Australia are among the most expensive in the world when rents and household incomes are taken into account.

A new 24-country comparison of house prices by the IMF showed that Australian house prices are behind just those of Belgium and Canada when judged by two measures: the ratio of house prices and incomes, and prices to rents.