A nine-day old dolphin has died at a water park in Bulgaria - amid reports it was 'overworked'.
The baby animal died during a performance, according to local media, although attraction owners claim this was not the case.
A witness said there was a "disturbance" at the Varna Dolphinarium in Varna in front of a large audience.
Bisser Lyubenov told BTV Novinite that the crowd was ordered to leave as the tragedy unfolded.
It is claimed that dolphins are forced to perform four times a day, sparking outrage.
The witness said: "There was a disturbance, the dolphins stopped playing and performing tricks."
Animal charity Four Paws claims five dolphins and a seal have died there over the past five years.
Representative Yavor Gechev told the BBC : "This means categorically that conditions don't meet even the minimal standards for keeping such animals.
"The animals are struggling there, they are not surviving."
The venue denies the infant dolphin's death happened during a live show.
Biologist Tsvetan Stanev told the BBC that using an animal that young had "never happened" in a show.
He said dolphins are not used in displays until they are around six months old, and not separated from their mothers in their early days.
Now a petition has been launched calling for the Dolphinarium to be closed.
It states: "Dolphins are intelligent creatures and deserve to be at large!"
