Insurance Fraud?

What is your question?

I would like to know about reporting a potential insurance fraud issue, coupled with employment underpayment. I am dealing with a mechanic who receives estimates from the insurance company for a repair. The estimate quotes a particular number of hours and new parts. The mechanic then directs his employees to complete the job in fewer hours, with used parts. Mechanic then bills the insurance company for the original estimate (with extra hours and new parts that were never used). He is defrauding the insurance company and short selling his employees. Who can I report this to? Better Business Bureau? Bureau of Automotive Repair?