Poison at Wanstead Flats lake kills dozens of birds and a dog

Police and wildlife experts are investigating the poisoning of more than 70 birds and a dog at a park lake.

People have been warned to stay away from Alexandra Lake on Wanstead Flats and keep pets on leads. The area has been taped off.

Bodies of the birds have been recovered from the surroundings of the lake and are being examined by vets. Species include crows, geese and other waterfowl.

One local birdwatcher described how birds had been "falling out of the trees almost constantly since Tuesday".

Jonathan Lethbridge, who writes the Wanstead Birder blog, said: "When I looked at the area from the car today it seemed very empty. The keeper I spoke to has been picking up crows and putting them together while they die. The whole thing sounds horrible."

He said the species also included Canada and greylag geese, coots, moorhens and pigeons. But swans and ducks appeared unaffected.

The dog, a German shepherd cross, had only been let off its lead for five minutes while the owner took it for a walk on the flats. It died within minutes of returning home.

A spokeswoman for the City of London Corporation, which maintains Wanstead Flats, said: "There have been unexplained bird deaths on and around Alexandra Lake and we have also received details of the death of a dog that was taken for a walk in the area on 8 March.

"The area has been cordoned off and warning signs have been erected."

Wildlife agency Natural England said its officers had collected the corpses of about 70 birds and sent them to its laboratory to establish cause of death. The agency is working with the police wildlife crime unit.

Epping Forest keepers are patrolling the site around the lake.