u.s. justice department and other federal agencies, which are investigating danske bank. it's cooperating with the investigation, as are j.p. morgan, bank of america, and deutsche bank u.s.a. none of the banks accepted our requests for interviews. the case could end up with hundreds of millions of dollars in fines, and under u.s. whistle-blower laws, howard wilkinson could potentially share in the proceeds. i mean, you were the whistle- blower in this case, correct? >> wilkinson: i guess so. >> kroft: under u.s. law, you could end up being rewarded with a substantial amount of money. >> wilkinson: back in december '13, the idea that this would be a case that the u.s. department of justice and s.e.c. would ever have any interest in would never even cross my mind. you know, the bank should've investigated it, sorted it out. what happened? basically nothing. it's shocking. >> kroft: it's impossible to say exactly where the $230 billion of dirty money originated, beyond the banks of moscow. it's been estimated that about a third of the russian economy is off the books. awash in cash, much of it is from corruption, bribes, and tax evas