The number of high-income families living in rent-controlled property fell by 94,000 to 695,000 between 2009 and 2012, according to new research on the Dutch housing market.

The government is allowing landlords to bump up the rents paid by high earners living in social housing, in an effort to encourage them to move to the private sector or buy their own home.

Housing which costs below €665 a month is by law reserved for people earning less than €33,000 a year.

The research also shows free sector rental properties now account for 12% of the rental housing market, compared with 7% in 2009.