AN oily film seen floating on the water at a popular beauty spot is 'not pollution,' according to the body which maintains the site.

The City of London Corporation claims the substance, which has appeared on the surface of the boating lake at Hollow Ponds in Snaresbrook during the past week, is caused by pollen and not oil - as feared by some nature lovers.

One dog walker told the Guardian that his pet had become reluctant to enter the water to fetch sticks because of the residue, which had formed a foaming slick at the edges of the water.

But a spokeswoman for the corporation said the film, which has also been seen on Eagle Pond in Snaresbrook Road, was harmless.

She said: "At this time of the year the water in Hollow Ponds is generally glazed by a fine layer of pollen fallen from the willow trees around which can sometimes be easily misinterpreted as oil pollution.

"Another indicator of the good water quality at the ponds is the large amount of dragonflies and damselflies which would not be present if there was water pollution.

"Dog owners are not encouraged to let dogs go into the water as they may intimidate wildlife in the ponds."

Complaints have also been made about the large amount of litter left scattered on the ground and in bushes around Hollow Ponds - a situation that was exacerbated by a rise in visitor numbers during the warm weather on the weekend.

The spokeswoman said the corporation was doing its best to deal with the problem.

She said: "Hollow Ponds is a boating lake and as such is difficult to patrol particularly when it comes to littering.

"Litter is picked up several times a week and we are doing everything we can to tackle the issue over the summer but litter does pile up particularly during weekends with good weather.

"We encourage visitors to enjoy summer in Epping Forest and Hollow Ponds the same way as they would in their own back gardens and take their rubbish home with them."