The US National Labor Relations Board (NLRB) accused rocket and satellite manufacturer SpaceX of illegally firing some employees who criticized the company's chief executive (CEO) Elon Musk.

In a complaint filed by the NLRB's regional office, 8 employees were allegedly fired in 2022 for urging SpaceX to distance itself from social media comments in which Musk mocked accusations of sexual harassment.

The letter distributed by the employees also called on SpaceX to clarify its harassment policies and apply them consistently, the complaint said, adding that the distribution of the letter was illegally restricted.

The complaint also accused SpaceX of questioning employees about the letter and threatening to fire workers who engaged in similar activities.