A chimp who has grown up among humans may have developed the ability to talk, claims a research team from the US.
The findings, published in New Scientist magazine, may come under fire from other scientists.
But they may further challenge the long-held belief that apes have no language ability.
Kanzi, an adult pygmy chimp, is kept at Georgia State University in Atlanta, and, like many other primates, can communicate by pointing at symbols.
However, researchers recently noticed that he was also making gentle noises while he interacted with humans.
By studying many hours of videotape, Dr Jared Taglialatela and Dr Sue Savage-Rumbaugh spotted four distinct sounds that accompanied particular actions, corresponding to “banana”, “grapes”, “juice” and “yes”.