Swimmers have been warned against wading into the Hackney Marshes river or risk catching diseases and disturbing the wildlife.

Hackney Marshes User Group (HMUG) has seen an increase in would-be wild swimmers coming to the River Lea during the coronavirus lockdown, especially during the hotter weather in May.

Co-ordinator of the group, Tim Evans, is asking people to leave the river alone - not only because it is dirty but also because it is home to kingfishers and owls.

READ MORE: Arrest powers granted for Hackney Marshes after spate of gatherings“It’s become very pressing,” he said. “There have been lots of people down in the old River Lea, which is a valuable wildlife site, with owls nesting there for the first time last year.

“The water there is quite shallow, it looks lovely and clear, but actually it is one of the most polluted in the city.”

Kingfishers are on the RSPB’s amber conservation list, which means it is the critical level behind globally threatened.

Tim added: “This year in May and in lockdown, it has been absolutely rammed and promoted as a place to swim.

“It’s not sensible for people to be splashing in the Lea. If you do, you could catch coronavirus or diarrhoea or other diseases and I don’t think serious wild swimmers would want to go there anyway.

“Consequences for people are not good and the consequences for the wildlife are very sad.”

He said there was a “balance” to be struck between people having fun during lockdown and preserving a “unique place” in inner London.

A spokesperson from Hackney Council said: “The River Lea is polluted and unsafe for swimming. We would urge people to avoid gathering and swimming in the area.”

This comes as activists from Save Lea Marshes and CPRE London have started a campaign to transform the historic filter beds on Lea Bridge Road into a place for wild swimming.

The proposed site would link up Leyton and Walthamstow Marshes, the Waterworks Centre Nature Reserve, Hackney Marshes and Middlesex Filter Beds and the river and towpath to the west.

A petition calling for the project has reached more than 4,000 signatures: www.change.org/p/waltham-forest-council-create-a-place-for-wild-swimming-in-waltham-forest-now