I'm not saying this as some sort of matter of moral conviction. I can't speak for Australia, but in the U.S., if you are found in possession of stolen property, you have to give it back. And if a prosecutor thinks they can prove you knew or should have known, they can charge you with a crime. I don't see why businesses should get a pass on this when individuals don't.

If I rob a bank and use a bunch of marked bills to buy a nice dinner, the restaurant doesn’t get to keep that money when the police come knocking, does it?

The courts will do the investigation for you. Why not have insurance on your end, in case the government seizes the money because it wasn't the criminal's to give to you?