NBC is vowing “further investigation” into what’s going on at “America’s Got Talent” following its “productive” meeting with Gabrielle Union, and a new report alleges that exec producer/judge Simon Cowell is at the heart of it all.

Union tweeted that she met with NBC executives on Tuesday in a five-hour meeting that she described as “productive.”

Union’s firing as a judge from “AGT” last week led to allegations of a “toxic culture” on the set of the family-friendly talent competition, including reports that she was told her hairstyles were “too black”. In addition, Union was reported to have clashed with Cowell over his insistence at smoking indoors when tobacco smoke seeped from his dressing room into hers.

RELATED: Gabrielle Union Confirms ‘Productive’ 5-Hour Meeting With ‘America’s Got Talent’ Producers Following Backlash Over Her Firing

“I was able to, again, express my unfiltered truth,” wrote Union in her tweet. “I led with transparency and my desire and hope for real change.”

On Wednesday, an NBC spokesperson told Deadline the network was planning to open an investigation into the show after hearing Union’s concerns.

“The initial conversation was candid and productive,” said the spokesperson. “While there will be a further investigation to get a deeper understanding of the facts, we are working with Gabrielle to come to a positive resolution.”

RELATED: Howard Stern Accuses Simon Cowell Of ‘Orchestrating’ Gabrielle Union Controversy On ‘AGT’, Eva Longoria Slams NBC Over Union’s Departure

According to Deadline, that “further investigation” will include Cowell. “Deadline has learned that the discussion yesterday revolved in no small part around the acerbic Brit’s behaviour and overlording of the Fremantle and Cowell’s Syco-produced ‘AGT’.”

Added an insider: “The ball is in NBC’s court to see if they can get Cowell to agree to make some changes to the way things are done on the show.”

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