I read they will turn over the money to the authorities.
if the money is proven to have come from an illegal source, yes, it is part of AML regulation(as far as I know), as members have already mentioned, the casino doesn't keep the money, they must report if they believe the funds from an account came from an illegal source. also, if casinos don't report incidents like this, they will most likely lose their license and face penalties.
that's what I was actually looking out for. There is every possibility that the money wouldn't get to the authority even after it's been withheld from the person's account but I guess to avoid sanction they wouldn't want to keep the money to there self.
But the main issue is how to identify that a particular money is from a fraudulent means or not. People have sources of income that's not all that illegal but that's also not that genuine to have made it public as an occupation or so and if that's going to be the reason for ceasing a person's fund it might be a bit unjust.