Traps are to be laid to snare a creature which has been stealing and eating an east London river's wildlife.
An alligator snapping turtle could devour a lot of the river's wildlife
Originally thought to be a crocodile, experts say it is more likely to be an alligator snapping turtle which can grow up to 2m (6.6ft) long.
Giant traps, similar to lobster pots, will be set in the River Lea to catch the animal alive. It is thought it was probably a pet that was set free.
If left, the 'turtle' could eat a lot of the river's natural inhabitants.
Concerns about a creature arose when a party of boat trippers saw a goose snatched from the water's surface.
Mark Gallant, of the Lea Rivers Trust, told BBC News: "I would like to say 'why don't we leave it there?'."
"But it can live up to 100 years and if you do a rough calculation about how much wildlife it could take out in a hundred years - well that's quite a few birds and fish from the Lea Rivers who could feel the full force of it.
"It's really got to go - otherwise it too may come to a sticky end."
Mr Gallant said that when and if the 'turtle' is caught, it will be found a home at a nature park here in the UK.
So far the summer tides have made it difficult for the traps to be set, but Mr Gallant hopes to get them in place soon.