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:
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Matthew Scully-Hicks, from Cornwall, denied killing Elsie Scully-Hicks in May last year.
Charges include conspiracy to produce cannabis, abstracting electricity without authority and conspiring to hold another person in slavery.
Bristol man, Jordan Walters, has been jailed for two years after an 18-month-old was shot in the head with an air rifle.