SAN FRANCISCO: Google said Friday it fired a lead artificial intelligence ethics researcher, following controversy last year over the tech giant's dismissal of a Black colleague who was an outspoken diversity advocate.

"I'm fired," Margaret Mitchell announced on Twitter.

Google told AFP that after reviewing "this manager's conduct, we confirmed that there were multiple violations of our code of conduct, as well as of our security policies, which included the exfiltration of confidential business-sensitive documents and private data of other employees."