A spokesperson from the Scottish Environment Protection Agency (SEPA) said:
SEPA takes water quality samples at each designated bathing water throughout the bathing season (1 June to 15 September).
“The water quality at North Berwick (West) has a good classification, however a sample taken at the bathing water on 1 August 2016 has shown pollution to be present at an elevated level.
“SEPA is carrying out an investigation into this and is in contact with all relevant partner organisations.
“Further samples have been taken and it is hoped that the bathing water will return to the normal good standard very soon.”