[zwog]

Semi related: A couple of years ago a waste facility in Berlin measured increased levels of radio activity and traced it back to a restaurant where 13 cards laced with radioactive Iodine-125 were found:

https://www.bbc.com/news/world-europe-42157129

I couldn't find anything about how the cheat actually worked, though. In Mongolia they found radioactive dice at an airport: https://conferences.iaea.org/event/16/contributions/7187/att...