The pollution may have taken place out to sea

Eider ducks, cormorants and guillemots have been taken to the SSPCA's bird cleaning centre near Inverkeithing.

Inspectors are checking beaches in the Elie, Kirkcaldy and Methil areas for more stricken birds.

There is no evidence of inshore pollution. They may have been covered by an spill offshore in the North Sea.

The Coastguard Agency is investigating the source of the oil which is contaminating seabirds in the Firth of Forth.

My biggest fear now is that this is going to escalate into huge numbers, possibly talking about hundreds of birds Sandra Bonar Middlebank Wildlife Centre

Forth Coastguard spokesman John Mayston said: "We have taken samples of oil off the birds and we have now asked surveillance aircraft to come to the Forth area to see if they can see anything which is causing these birds to be oiled."

A tanker which left Grangemouth last week may have been leaking.

Tests are being carried out on the oil taken from the birds to establish the source.

Sandra Bonar, from the Middlebank Wildlife Centre near Dunfermline, said: "They were coming in in manageable quantities at the weekend, say about three or four a day, but it's actually been building up over time.