Ruislip Lido has been fenced off following an outbreak of toxic algae that can be fatal for dogs.

The site by Harrow and Rickmansworth is popular on sunny days but following the recent heatwave there was an outbreak of blue-green algae.

Under government guidance, Hillingdon Council has had to close the water off to the public as a precaution to ensure people and pets stay out of the water.

The bloom of blue-green algae naturally occurs in hot and sunny weather and the Environmental Agency states that it can produce toxins that could kill animals, livestock and pets.

The agency said: "They can also harm people, producing rashes after skin contact and illnesses if swallowed."

While the weather is expected to continue cooling down the Met Office has predicted that the hot weather could return in just a matter of weeks – which is likely to contribute to even more blooming algae.