I heard about this at one of the banks I worked for in the 1990's.
This was told to me as it was happening by someone in a position to know, but not in a position to do anything about it.
A trader stole millions of dollars from the bank using the "trade tickets in the drawer" method. I don't remember how much but it was truly an enormous amount of money.
When he was detected in his theft the bank declined to press charges and covered the whole thing up out of fear that he would ruin their reputation by being in the press and explaining how stupid and weak the bank was (it had a sterling reputation among its customers).
So he was allowed to leave with the millions he had stolen and given a good reference!
He went to work a few days later for a trading location "across the street."
I was told this was not an uncommon thing, where insiders were allowed to get away with what they stole in return for keeping quiet and supposedly preserving the reputation of the bank.
The only evidence I have is that this person was really scared when this person told me and especially when the bank got busy trying to find out who inside knew about this. This honest and really hard working person was really, really scared and wished that he or she did not know about it for fear of being purged or something.
And you wonder why the problems have all come home to roost, and people like me have suffered for not being an insider at the dishonest pig trough.