The killer whale which was recorded mimicking human speech could be saying "set me free", says an animal campaign group.
Scientists have recorded an orca named Wikie mimicking a trainer to say "hello", count and blow raspberries.
Critics say it only proves what is already known about whales' intellect and doesn't promote conservation.
The charity Born Free's president Will Travers said: "The natural place for a whale or dolphin is in the wild."
"I can't quite imagine why this is in the headlines as there are lots of different animals - lots of different species - that can mimic humans," he added.
"They could actually be saying 'set me free' for all we know."
Researchers had set out to discover whether orcas could learn new vocalisations by imitating others.
Dr Josep Call, a University of St Andrews co-researcher on the study, said the findings showed whales were among a small group of animals able to mimic human speech.
He said it showed basic "conversations" with Wikie could one day be possible.
Scientist Dr Peter Evans, from Sea Watch Foundation - which works to improve whale conservation - said the study was an example of "anthropomorphism"- a human desire to see our own traits mirrored in animals.
"We're not really learning much more by doing these studies in captivity.
"What would be great is if we learned more about how they communicate in the wild together."
The study has also brought attention to the life of whales in captivity.
I think she should be in the ocean. Perhaps if she really could talk she would say is a whale, not a parrot, and that she wants to be free. The killer whale that can say 'hello' and 'bye bye' - BBC News https://t.co/Uy4eYwBpKL— Keith Anthony (@KeithAnthonyWS) January 31, 2018
Wikie lives at the Marineland Aquarium in Antibes, France.
The country last year banned breeding or keeping dolphins and killer whales in captivity, except for orcas and bottlenose dolphins already held.
Born Free's Will Travers said the study was the result of an "unnaturally close proximity" that only served human entertainment.
Orcas kept in captivity were known to suffer from physical and psychological issues, including developing the hallmark collapsed dorsal fin, he added.
"I think we've got to wise up. The natural place for a whale or dolphin is in the wild."
But releasing orcas bred in captivity, like Wikie, to the open sea is not straightforward,
There are few examples of captive marine mammals being successfully freed. In 2003 Free Willy star Keiko died, 18 months after being released into the wild in Iceland.
It's believed many animals would require intensive monitoring, and might not ever be able to be set fully free as they had never had to hunt or navigate before, spokesman Danny Groves said from the campaign group Whale and Dolphin Conservation.
The group wants to see the creation of netted sea sanctuaries where whales could be trained to thrive independently.
A prototype sanctuary is currently being developed in Iceland for "retired" captive beluga whales, Groves said.