A group of Amazon engineers say they are under internal investigation after publicly criticising the rapid expansion of artificial intelligence data centers and calling for tighter government regulation.

Earlier this month, five Amazon employees spoke at Seattle City Council hearings during a public consultation on a proposed one-year pause on new large-scale data center construction, aimed at giving the city time to develop regulatory frameworks.

The council unanimously approved the moratorium on June 9.

During their remarks, the employees also questioned the heavy AI investments by major tech firms, describing the trend as an “all-costs-justified AI buildout.”

Following the hearings, three Amazon workers were separately called into Zoom meetings with a human resources representative who said he was investigating concerns raised about their testimony, according to a complaint filed Friday with the Seattle Office for Civil Rights.

The complaint, submitted by lawyers representing the employees, states that the workers were told the probe could result in disciplinary action, with one employee informed that penalties could include termination.

It also alleges that Amazon’s questioning left the staff feeling “intimidated and uncertain in their future employment.”

“They also learned that Amazon was monitoring their political advocacy before the Seattle City Council and was seeking to identify additional employees who had engaged in political activities,” the complaint said.

The complaint alleges that Amazon breached a Seattle ordinance that bars employers from discriminating against workers based on political ideology, race, religion, age, and other protected characteristics.

Amazon spokesperson Margaret Callahan said in a statement that the company does not allow employees to speak on behalf of Amazon unless they follow established internal procedures.