Financial crime can't exist truly hidden in the modern world. Someone always know about it happening. So bribing those in the know is an integral part of the financial crime. And at certain scale bribes get to be renamed as lobbying, while being in essence the same bribes. Bribes are illegal, but lobbying is not, that's what the reward is. Corporation get to legalize their ill gotten money and have no problems with the law.

You don't want to pay capital gains taxes, so you lobby that it is legal to separate obviously unified entity into on-shore bankrupt one, and off-shore profitable one in Ireland or whatever, bribed politicians make it a law and suddenly no taxes are required. You have a chicken farm for which you don't want to pay for extremely expensive utilization of the ill and dead birds, so you lobby to reduce some restrictions written in law and voila, now you can dump your dead birds at a common garbage dump. These are just some illustrative examples.