The only elephant in Kiev's zoo, 39-year-old Boy, died Monday in his enclosure, apparently after being poisoned, the zoo's director said.
"This morning at 10.45 a.m. he let out a terrible cry and fell. I have the conclusions of veterinarians ... It was a poisoning," zoo director Svitlana Berzina told Reuters.
Boy, a 6 1/2 metric ton Asian elephant, arrived in Kiev zoo in the mid-1970s.
"It was a tragic and sudden death," she said. "The animal was in stable condition and nothing indicated any trouble. It was an instantaneous death."
Berzina said there had been an earlier attempt to poison Boy in the 1990s. "On that occasion, we managed to save him," she said. The circumstances of this previous attempt to poison Boy were not clear.
"The reasons for his death will be the subject of an investigation by veterinarians and law-enforcement bodies," Maria Azoryan, a Kiev city administration official, said.
Berzina said the preliminary reason for the elephant death was acute heart and lung deficiency.
The zoo had called for help to prosecutors and independent experts to investigate, Berzina said.
Boy's corpse remained covered by a tarpaulin inside his open enclosure Monday. Zoo authorities said there would be an autopsy Monday night.