Millions of home owners are failing to report crimes because they fear their neighbourhood will gain a bad reputation from scoring high on police crime maps.
At the same time, latest Home Office crime figures show the number of burglaries has risen 14%, pushing up home insurance costs.
Research by Direct Line insurance revealed 5.2 million home owners were worried telling the police about drug dealers, vandalism or car thefts because they feared the disclosure would affect the price of their home or the rent they could charge tenants.
Around 75% of renters and home buyers say they check out crime maps before viewing a property.
Almost half of those not reporting crime witnessed cars stolen or vandalised near their homes.
Some did not tell police about serious street crime like assault or robbery.
Meanwhile, as the number of burglaries soared 14% in 12 months, Allianz Insurance predicts a continuing rise in crime.
Insurers confirm increasing claims for burglary are triggering more home insurance claims with the average claim value rising.
Mark Bishop, of Allianz Insurance UK, said: “We also undertook this research in 2008 when people were already concerned about crime. Since then, the average claim on our house insurance for theft has jumped by £227.
“Worryingly, our research has revealed that one in 10 Brits have not even considered security measures for their home – in the current environment we are urging homeowners to review their home crime prevention measures as a matter of urgency.”
Insurers argue householders could prevent many burglaries by installing better security.
Around 70% don’t have a burglar alarm, while more than 30% do not have door and window locks and another 43% leave doors and windows open at night.
“This negligence is often down to a naive attempt to save some money but backfires sometimes when insurers reject claims,” said Bishop.