There's already a moral hazard, either blackmail from the investigator, or bribery from the subject.
Planting $50 million to get $2 million. Not a terribly good deal.
Implicating (wrongly) someone else's $50m to get $2m. A tempting deal for some.
You can neither make 50 Million appear nor can you plant evidence in Bank data that the victims lawyers couldnt tear to shreds. Accounting isn't dropping a joint in someone's pocket