The disappearance of a Canada goose on the River Lea has resurrected questions over whether a mystery beast lurks in its waters.

An east London canal boat owner recently witnessed the fully-grown bird – which can weigh up to 14lbs – vanish under the surface.

It has reignited theories that a predator – possibly a large pike, mink, turtle or even a crocodile – is feeding on the birds, snatching them from under the water.

A group of biologists saw a Canada goose dragged under the river’s waters in very similar circumstances near the Olympic Park in 2005.

Photographer Mike Wells, 52, was on his boat near Leyton Marshes last month when he saw the latest vanishing.

He said: “About 30 metres or so away this goose went vertically down into the water with a very slight amount of splash. We watched for a while to see if it came back up and it didn’t.

“I figured out it must be this same creature that was reported back in 2005.

“There is a big predator in the water and the swan numbers are going down.

“Some people I’ve spoke to thought it could be a very large pike and I’ve seen some turtles which are about a foot across but they’re not really big enough to take a goose.”

Mark Gallant, of the Lea Rivers Trust, who saw the goose vanish in 2005, said at the time it was thought a hungry crocodile could be the culprit.

But speaking about the latest mystery, Leela O’Dea, a British Waterways ecologist, said the most likely predator was a mink.

She said: “They are known to go for ducks or small geese.”

“The other possibility is a terrapin. They do grow to dinner-plate size. But they’re more likely to go for ducks and ducklings.”