An increasing number of motorists are at risk of invalidating their car insurance cover by telling lies to get a better deal, it has been claimed.The Association of British Insurers (ABI) reported a rise in the number of fraud cases uncovered by providers.It stated one common deception involved parents adding a child to a policy as an occasional named user, when in fact the son or daughter is the main driver of the vehicle in question.The group also revealed a growing number of customers were failing to disclose motoring convictions.Commenting on the findings, Nick Starling from ABI said lying to get cheaper cover could have "disastrous consequences".He stated: "Being truthful and shopping around will mean that your insurance delivers when you need it and that you get the best possible deal."In related news, ABI recently called on road safety groups and the government to join forces with it in order to cut the number of whiplash-related motor insurance claims.