Japanese used car dealer Bigmotor's scandal over fraudulent auto insurance claims has spotlighted its cozy relations with major insurers.

Nonlife insurance companies introduced repair shops of Bigmotor, their partner, to policyholders who had car accidents. The insurers, for their part, won new automobile liability insurance contracts for used cars sold by Bigmotor, informed sources said.

According to an investigative report by outside lawyers, it was common practice among Bigmotor employees to deliberately damage cars and perform unnecessary work in order to pad maintenance fee claims submitted to insurers.