The Securities and Exchange Commission is investigating whether OpenAI investors were misled as the startup went through a ferocious debate over leadership last year, the Wall Street Journal reported, citing people familiar with the probe.

The US regulator is studying internal communications by Chief Executive Officer Sam Altman in relation to his ouster from the post in November, the report said. The SEC sent a subpoena to the company in December and asked senior OpenAI officials to preserve internal documents, according to the people.