Alphabet Inc’s Google fired staff scientist Margaret Mitchell on Friday, they both said, a move that fanned company divisions on academic freedom and diversity that were on display since its December dismissal of AI ethics researcher Timnit Gebru.

Google said in a statement Mitchell violated the company’s code of conduct and security policies by moving electronic files outside the company. Mitchell, who announced her firing on Twitter, did not respond to a request for comment.

Google’s ethics in artificial intelligence work has been under scrutiny since the firing of Gebru, a scientist who gained prominence for exposing bias in facial analysis systems.

The dismissal prompted thousands of Google workers to protest. She and Mitchell had called for greater diversity and inclusion among Google’s research staff and expressed concern that the company was starting to censor papers critical of its products.

Gebru said Google fired her after she questioned an order not to publish a study saying AI that mimics language could hurt marginalized populations. Mitchell, a co-author of the paper, publicly criticized the company for firing Gebru and undermining the credibility of her work.

The pair for about two years had co-led the ethical AI team, started by Mitchell.

Google AI research director Zoubin Ghahramani and a company lawyer informed Mitchell’s team of her firing on Friday in a meeting called at short notice, according to a person familiar with the matter. The person said little explanation was given for the dismissal. Google declined to comment.

The company said Mitchell’s firing followed disciplinary recommendations by investigators and a review committee. It said her violations “included the exfiltration of confidential business-sensitive documents and private data of other employees.” The investigation began Jan.19.