Burglars are set to cash in on £750m from people leaving their keys lying around their homes, a leading insurer has warned.

Norwich Union Insurance has said that with doors and windows being left open in the hot weather, burglars will find it easier to get into homes this summer, and that they are set to steal £2,405 worth of contents per household.

The insurer’s 2006 Cash for Keys Report, revealed that 80% of Brits have up to five sets of keys in their home, with a half keeping them all in one place. To make matters worse, 12% puts labels on keys, giving thieves clear directions for a fast hit.

Norwich Union urged people to take notice of the celebrity homes that had been burgled specifically to steal keys to prestigious cars, as a reason why they should take more care.

England footballer, Frank Lampard was robbed of his Mercedes and Aston Martin last year which had a joint value of £195,000. And Last month, the former Arsenal player Patrick Vieira and his family were gassed by burglars who then drove away with his £40,000 Mercedes and valuable jewellery.

Paul Redington, claims manager from Norwich Union said: “The research findings have highlighted some pitfalls in home security allowing thieves to cash in on a jackpot of keys, that literally open the doors to cars, motorbikes, garages, safety deposit boxes and neighbours houses.

“Home owners should ensure all windows are shut when ever they leave their house. When on holiday, the house should be left secure and we would advise limiting the number of people who know your home will be left empty for this period of time. Most importantly, lock car and spare keys in a secure place during you holiday.”