Major insurance companies are denying home insurance or refusing claims to households where somebody has a criminal conviction, according to a new study.

Five out of six leading companies approached by a researcher posing as an ex-offender - with a conviction for assault rather than fraud or theft - refused him building or contents cover because of his criminal record. Direct Line and Lombard Direct said they could not offer cover until 10 years after the conviction; Egg and Churchill would only offer cover after five years; and Eagle Star said it would not offer cover under any circumstances.