A property search engine that uses Google Maps to display houses is going one step further by adding prices of sold properties to the map.

OnOneMap uses a customised version of Google's mapping service to display houses on a map rather than in a list. Users can click the icon of a house to find out its price and other details. The site lists homes for sale or rent from several agents.

The company, which is now a year old, was set up by a disgruntled home buyer who was fed up with having to switch between several estate agents' websites.

In order to check the prices of houses that have been sold, OnOneMap is now adding data from the land registry that will show how much other properties have been sold for in the same area.

The purpose is to allow potential buyers to see whether or not they are paying over the odds for a property in a particular area or road.

The land registry house price data is already available as a custom Google map from House Price Maps but this is the first time both sold houses and homes on the market have been displayed in the same place.

Grey house icons indicate a sold property while coloured icons show properties currently for sale or rent.