Gabrielle Union has insisted NBC need to do more to address workplace harassment

She tweeted: "Great start by NBC to recognize the need to not turn away & ignore racial & gender discrimination on programs like #AGT

"More changes are needed however. Like stopping ex ecutives from intimidating talent from sharing their experience of racism in their own workplace investigations.(sic)"

Gabrielle's comments came in the wake of an article in The Hollywood Reporter, which claimed NBCUniversal TV and streaming chairman Mark Lazarus had sent a memo to staff, in which he detailed the company's move to expand protections for employees against toxic workplace environments on shows produced by both the network and third-party companies.

Gabrielle filed a discrimination complaint against NBC, Simon Cowell, FremantleMedia and Syco Entertainment in California's Department of Fair Employment and Housing last June.

However, it has since been closed as the Being Mary Jane' star requested an immediate right to sue, which she was granted.

Her official complaint came after NBC previously conducted an independent investigation into Gabrielle's allegations, but she was unhappy with how it was handled.

She previously said: "They were like, 'We're going to commission this independent investigation.' Well, silly me. I thought independent was independent, but when NBC and Fremantle and Syco pay for that investigation, they control it.

"They turn over what they believe to be inflammatory things, or things that are not advantageous to me, over to the head of NBC, Paul Telegdy, who uses those things that he thinks are smoking guns to shoot down my claims.

"He then threatens my agent [by saying,] 'Gabrielle better watch who she calls a racist' in the middle of an investigation about racism and discrimination. This is what's happening from the top of the company."

NBC previously insisted it was "categorically untrue" that any threats had been made towards the star.

They said in a statement: "We took Ms. Union's concerns seriously, and engaged an outside investigator who found an overarching culture of diversity on the show. NBCUniversal remains committed to creating an inclusive and supportive working environment where people of all backgrounds are treated with respect."