Debra Messing has hit out at NBC for ''disgusting behaviour'', amid claims that Gabrielle Union was ''fired'' from 'America's Got Talent'.

The 51-year-old actress has starred on 'Will & Grace' on the network since 1998, but she has now slammed the company, which comes after allegations this week that Gabrielle had shared concerns about a ''toxic culture'' on the show.

Referencing a tweet from 'Grey's Anatomy' actress Ellen Pompeo, she wrote: ''Thank you for this @EllenPompeo. This is disgusting behavior from a network that has been my professional home for decades. Yes, women become ''difficult,'' when their insistence on a respectful and professional working environment, is ignored. Addressing a hostile work (sic)''

Ellen had tweeted: ''It's unfortunate that @nbc the same network that protected disgusting men like Matt Lauer and punished women for speaking out or not putting up with it...has not changed their practices or culture. I support @itsgabrielleu commitment to speaking up to injustice. It takes courage (sic)''

The pair's comments come after Gabrielle's husband Dwyane Wade claimed she was ''fired'' from 'America's Got Talent', after it was confirmed this week that she and Julianne Hough are to leave the panel of the talent show.

He tweeted: ''Men lie, Women lie, numbers don't'' Over this past year I've been approached by many people saying that my wife @itsgabrielleu is the main reason they've started watching #AGT or that they love her insight and sincerity on the show.

''So when i got the news that my wife was being fired - my first question was obviously why!? Iam still waiting on a good answer to that question. But if anyone knows @itsgabrielleu or have heard of her you know she's an advocate for our community and culture. (sic)''

Gabrielle has also liked a tweet which claims she was ''fired''.

It read: ''The first public word from @itsgabrielleu after she was fired last Friday by NBC (sic)''

Gabrielle has opened up about feeling ''humbled and thankful'' after all the support she has received this week.

While she didn't refer directly to 'America's Got Talent', she wrote: ''So many tears, so much gratitude. THANK YOU! Just when you feel lost, adrift, alone... you got me up off the ground. Humbled and thankful, forever (sic)''

It comes after reports this week claimed Gabrielle called for Jay Leno to be reported over an offensive joke he made while recording 'America's Got Talent'.

And insiders telling Variety about a ''toxic culture'' at the show recalled how Gabrielle and other members of staff shared concerns about a white male auditionee whose act involved rapid costume changes into famous singers, with one meant to be an impersonation of Beyonce Knowles with black hands.

According to the sources, the judge ''immediately'' advised a segment producer and an executive producer to remove the contestant from the line-up but they declined and said: ''We'll take it out later''.

However, Gabrielle pushed further and insisted the studio audience shouldn't be subjected to seeing the act, but he still made it to the stage and his audition was later cut from the episode.

Show producers insist they embrace ''inclusivity and diversity''.

NBC and Fremantle said in a statement: '''America's Got Talent' has a long history of inclusivity and diversity in both our talent and the acts championed by the show.

''The judging and host line-up has been regularly refreshed over the years and that is one of the reasons for AGT's enduring popularity. NBC and the producers take any issues on set seriously.''