The last surviving gorilla from the 1988 drama, Gorillas in the Mist, is believed to have died after disappearing for almost a year.
The gorilla, who was known as Poppy and would have turned 43 on April 1, has not been seen by trackers since last August, according to the non-profit organisation which cares for her.
Poppy was born nine years after Dian Fossey established a camp within Rwanda's Volcanoes National Park.
Set up in 1967, it was an effort to study the area's disappearing mountain gorilla population.
The classic film follows the story of Dian Fossey, a scientist who came to Africa to study the vanishing mountain gorillas, and later fought to protect them.
People who monitor Poppy said she has not been seen since last year, following a series of "stressful events" which happened to the group she lived with.
It is thought the death of a newborn gorilla, born in December 2017, after a violent attack by another animal could have led to her disappearance.
Whilst Poppy's death has not been confirmed, Fossey Fund keepers did share some positive news, stating: "It is still possible that we will see Poppy again and she has certainly surprised us in various ways before."
They added: "This type of situation has occurred before, most notably when the historic elderly silverback Cantsbee went missing from his group in October 2016 and could not be found despite weeks of massive searching.
"Then, in January 2017, he suddenly reappeared in his group and astonished our staff.
"However, he disappeared again in February and was confirmed to have died a few months later, when his decomposed body was located."