Chemists at Plymouth University have identified the sticky substance that has killed hundreds of sea birds off the Devon and Dorset coast.
Their findings suggest it's a form of Poly Isol Butene, or PIB, used as a lubricating additive in oils to improve performance.
Tamsin Eames reports:
More top news
It will be a mainly sunny day with blue skies at times. And yes, it will warm up.
Parents facing prosecution in Devon for taking their children out of school should have their cases dropped immediately says one leader.
Our correspondent Seth Conway brings us La Vélodyssée in the first series, which, as the name suggests, has a European flavour.