mystery stench

Something has died in our fridge. From the stench, it would appear to have been a fish of some sort. One opens the fridge door, and even after hastily closing it again, the stink wafts across the living room for another three minutes.

But where is this corpse hiding? I have cleared everything culprit-worthy out! Wizened slices of salami, cloudy-looking olives, past its sell-by date capers -- but none of these were fish-like! None of these smelled! And everything else is shrink-wrapped or a vegetable!

*despairs*