Boulas, a 27-year-old gorilla has died at Longleat Safari Park in Wiltshire.
The 200kg Western lowland gorilla, died on Tuesday after two years in the park.
Longleat said a full post-mortem examination would be carried out but early indications are that he died of respiratory failure related to an undiagnosed abscess in his throat.
Jon Cracknell, Longleat's director of animal operations, said: "This is a tragic loss and a cause for great sadness across the entire safari park.
"Boulas's keepers in particular have been devastated by the death of an individual they worked and lived with every day."
Longleat said Boulas had undergone a standard veterinary procedure to treat a suspected dental abscess.
Following recovery he suffered severe respiratory problems and despite the best efforts of the veterinary team, it was not possible to save him.
The silverback arrived at Longleat in 2012 from Twycross Zoo as part of a new state-of-the-art Gorilla Colony. Prior to moving to Twycross in 2010, Boulas had spent nearly a decade at Belfast Zoo.
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