The flesh-eating creature was found by a startled member of staff at Southern Water who was carrying out checks at the West Sussex treatment works.
The South-American river predator, which normally hunt in packs, can rip flesh to shreds in a matter of seconds.
Filed under WTF! Flesh eating fish (albeit a dead one), in the UK, in the sewer (no doubt with the crocodiles and the clown from IT!). #shudder