The ouster of Gabrielle Union as a judge on “America’s Got Talent” unleashed a storm of criticism in recent days after reports that before she was let go she had experienced racially insensitive behavior on set.

Now , the biggest actors’ union is investigating the show, helmed by Simon Cowell, and the leader of the anti-harassment group Time’s Up is taking aim at the network, NBC, for “protecting the careers of powerful men at the expense of women who speak out.”

“Not only did Union reportedly endure and witness racist and inappropriate behavior — including racially insensitive comments and excessive criticism about her physical appearance — but it also appears she was punished for speaking out: The company labeled her as ‘difficult’ before ousting her from the show altogether,” Tina Tchen, the chief executive of Time’s Up, said in a statement Monday.

On Nov. 22, the news broke that Union and Julianne Hough, who had joined Cowell, Howie Mandel and Terry Crews as hosts for the 14th season of “America’s Got Talent” this year, would not be returning. In the days that followed, Variety reported that Union had been let go after tense incidents that included her being repeatedly told that her hairstyles were “too black,” and her urging producers to report to human resources a joke Jay Leno made during a guest appearance in which he alluded to Koreans’ eating dog meat. (The joke was edited out before broadcast.)