After tests were carried out on a sample of the product, it was identified as polyisobutene, or polyisobutyliene (PIB). This is a fairly common chemical carried aboard ships and it is produced in a large number of countries.
Despite further tests, we have been unable to identify specific components of the product that may have helped us find the source. We did not receive any reports of pollution within the
English Channel area at the time when the birds were coming ashore, but a MCA counter pollution surveillance aircraft surveyed the English Channel from to the Isles of Scilly. In addition, images from the European Maritime Safety Agency’s satellites were reviewed. No pollution was detected. Dover
As such, we have concluded that it is highly unlikely we will be able to link the pollution to any specific vessel. Unless we receive any new information, our investigation is now closed.