Geoffrey Hinton, 75, announced his resignation from Google in a statement to the New York Times, saying he now regrets his job. He told the BBC that some of the dangers of AI chatbots were "quite scary".
"Right now, they're not more intelligent than us, as far as I can tell. But I think they soon might be."
Dr Hinton also admitted his age had played into his decision to leave the tech giant, telling the BBC: "I'm 75 so it's time to retire."
Dr Hinton's pioneering research on deep learning and neural networks has paved the way for current AI systems such as ChatGPT.
But the British-Canadian cognitive psychologist and computer scientist told the BBC that the chatbot could soon surpass the level of information held by the human brain.
"Right now, what we're seeing is things like GPT-4 eclipses a person in the amount of general knowledge they have, and eclipses them by a lot. In terms of reasoning, it's not that good, but it already does .simple reasoning.
"And given the rate of progress, we expect things to improve very quickly. So we should be concerned about that."
Is the world prepared for the next AI storm?
Artificial intelligence could affect 300 million jobs - report
In the New York Times article, Dr Hinton referred to "bad actors" who would try to use AI for "bad things".
When asked by the BBC to elaborate on this, he replied: "It's just kind of a worst-case scenario, kind of a nightmare scenario.
"You could imagine, for example, a bad actor like [Russian President Vladimir] Putin decided to give robots the ability to create their own sub-goals."
The scientist warned that this could eventually "create sub-goals like 'I need to get more power'".
"I have come to the conclusion that the kind of intelligence we are developing is very different from the intelligence we have.
"We are biological systems and these are digital systems. And the big difference is that with digital systems, you have multiple copies of the same set of weights, the same model of the world.
"And all these replicas can learn separately, but share their knowledge instantly. So it's like you had 10,000 people, and whenever one person learned something, they all automatically knew. And that's how these chatbots may know far more than any single person."
He stressed that he did not want to criticize Google and that the technology giant had been "very responsible".
"I actually want to say some good things about Google. And they're more believable if I don't work for Google."