Richard Ngo has become the latest employee to leave generative AI company OpenAI.

The AI governance researcher said that he was following his colleague Miles Brundage, who left three weeks ago.

"There was no single main driver of my decision," Ngo said in a company Slack post he shared on Twitter/X.

"I still have a lot of unanswered questions about the events of the last twelve months, which made it harder for me to trust that my work here would benefit the world long-term."

He added that "it's hard to convey how insanely ambitious OpenAI was in originally setting the mission of making [artificial general intelligence] go well. But while the 'making AGI' part of the mission seems well on track, it feels like I (and others) have gradually realized how much harder it is to contribute in a robustly positive way to the 'go well' part of the mission, especially when it comes to preventing existential risks to humanity."

Ngo said that "the sheer scale of the prospect of AGI can easily amplify people's biases, rationalizations, and tribalism." He added that he was "not immediately looking for other work."

OpenAI has been beset by a number of high-profile departures, many of which followed CEO Sam Altman's abrupt firing last year for not being “consistently candid in his communications with the board."

Altman was soon reinstated after a brief power struggle and has pushed to increasingly shift the once non-profit open AI research group into a for-profit, Microsoft-backed, closed AI business.

Since then, co-founder Ilya Sutskever left to start his own company, co-founder John Schulman left to join Anthropic, former safety leader Jan Leike departed, co-founder and president Greg Brockman took a sabbatical, and CTO Mira Murati left to start her own company, chief research officer Bob McGrew and VP research (post-training) Barret Zoph both quit in September, among others.

Those executives also took colleagues with them.

Throughout, however, the total number of OpenAI staffers has increased dramatically, as the company ramps up its generative AI products, and explores consumer hardware, semiconductors, and an increased data center presence.