Disability or Workmans Comp Fraud?

I know this guy pretty well and he has worked at Chrysler for about 8 years and he has spent 71/2 years on disability. This gentlemen has rotator cuff problems and has had surgery. After his surgery he did rehab and when he was getting ready to go back to work he pretty much re-tore it but did so on purpose. Now he has been through 2 surgeries and he told me that he is never going back to work and he is trying to go out on permanent disability. He is always doing strenuous work to re-injure his shoulder. Should I report him or can I even report him. He has openly admitted to me that he will never go back to work in the shop. I have seen him work harder at getting out of work than being like everybody else and going to work everyday. Who would I even contact if I were to report him? It is a shame but he thinks it is a joke but it is not to me. Can anyone help?