Celebrities are slamming NBC for dropping Gabrielle Union as a judge from America's Got Talent after she reportedly complained about a culture of racism and sexism at the show.

According to a Variety report, Union had raised concerns about racist incidents on set. She was also repeatedly told her hairstyles were "too black" for the show's audience, Variety reported.

Vulture reported that Simon Cowell, a producer and judge on the show, had labeled Union as "difficult" after she regularly complained about his indoor smoking habit. She also allegedly complained about several incidents on set that she perceived as being racist and sexist. Despite Union bringing the issues before NBC executives, "nothing would happen," sources told Vulture.

NBC decided not to renew the contracts for Union and Julianne Hough, another judge on the show, earlier this month.

In one incident reported by Variety, Union urged the show's producers to notify human resources about a racist joke that guest judge Jay Leno made while taping the show in April. Union reportedly said that the joke, which played on a racist stereotype of Asians, would offend the show's staffers and audience. While the line was cut from the episode, the matter was never brought to human resources, Variety reported.

Union also clashed with the show's producers after they allegedly implied that a 10-year-old black rapper was not an act "that America can get behind," Vulture reported.