Put an end to a dubious/shady business/activity

Hi, native English-speaking friends!

I wonder if you could help with a colourful and well-in-use expression for an idea of "putting an end to a business or activity that are either illegal or of shady/dubious nature". In Russian we have this expression "??????? ????????" (they've shut down the shop), like in: "I know a guy from whom one could buy monthly transport cards at half price. I haven't been able to contact him for two weeks. They (the authorities/the police) must've shut down the shop...

Thanks in advance

I wonder, if I could be of help