This was on drivetime radio 2 with simon mao last week - my OH came in and told me about it - it has to be liver with fluke in it - doesn't have to be well contaminated, only a tinsy bit, but its something to do with the fluke being attracted to the condensation on a milk bottle - it has to be a glass or a glass bottle. Someone put liver in a fridge and it ended up wrapped around the milk bottle by the morning.
Now, what I'd like to know is, who uses milk bottles these days and who on earth would put liver in a fridge without it being covered in clingfilm or in a bag. Don't fancy dinner at their house.