If this question is being asked because you're aware that it's happened and are wondering about whether to report it...
Then please, PLEASE, do. If it's been oversped to anywhere near that degree then there is a huge chance that significant damage has occurred which could easily lead to a catastrophic failure in the future.
It might be you flying, it might be someone you care about, it might just be some other poor sod. It MUST be reported. Even if it costs you your job - otherwise it could easily cost someone their life!
OH