The Reserve Bank is urging the Government to review its immigration policy in a bid to stem rising house prices.

The call comes just days after Prime Minister John Key told the central bank to ''get on with it'' and introduce new restrictions on property investors.

But Deputy Governor Grant Spencer says there are inherent risks with too much investor involvement in the property market.

Spencer says the government needs to recognise that the large inflow of migrants over the last three years has significantly boosted housing demand.

But he warns changes to immigration will only work at the margins, but they could eventually help calm the housing market.