Birds and patches of oil have been found on beaches

Oil patches have appeared on beaches from East Mersea in Essex to Felixstowe in Suffolk since Thursday morning.

Tests are now being carried out to find the source of the oil, with results expected in the next few days.

Chris McArthur of the Environment Agency said it could be from the sunken freighter the Tricolor in the English Channel.

But he said it was not thought to be from a leaking pipeline at Felixstowe Harbour which left 30 swans in need of treatment last week.

Full inspections

He added that overflights by the Coastguard Agency have not spotted any signs of an offshore slick.

The job of clearing up the spillage is the responsibility of the local authorities.

John Ryan, from Tendring District Council in Essex, said: "We first became aware of it yesterday when we did a full set of inspections and put out oil signs.

"It does appear it's along the whole of the coastline between Jaywick and Dovercourt now.

"But it's limited in its extent and we're clearing up any areas where we think there's sufficient for us to put machinery in."

Last December, a serious oil slick affected hundreds of birds on the East Anglian and Lincolnshire coasts.