A friendly dolphin found dismembered on a Cumbrian beach died of natural causes, scientists have revealed.
Marra was rescued from Maryport harbour in January
Marra, a female bottlenose, became a tourist attraction when she had to be freed from Maryport harbour in January.
Her remains were found cut up in sacks on Skinburness beach near Silloth, and it was feared she had been killed.
But a post-mortem examination carried out by experts at London's Zoological Society have found she died of blood poisoning from an infected wound.
Mark Simmonds, Director of Science for the Whale and Dolphin Conservation Society, said: "We will never be sure how this infection got into Marra's body.
"But the large number of wounds that she received and the fact that she was living in shallow polluted waters may have played an important role.
"As a tamed dolphin, Marra was very vulnerable to being struck by vessels, and especially their propellers.
"The lesson is that solitary dolphins are very vulnerable and it is important that they are not tamed by people, swimming with them, petting them or feeding them."
Marra became a regular feature in the port, but in October people were warned to stay away from her after she was spotted with several wounds, possibly caused by ropes or boats.
Allerdene Council is investigating claims that the animal was cut up by contractors for disposal after she was found dead last week.
The remains were left on the beach overnight and discovered by a member of the public.