Paul Telegdy, chairman of NBC Entertainment, told reporters at the Television Critics Association winter press tour Saturday that the network's investigation into Gabrielle Union's firing from America's Got Talent should be done by the end of January.

Back in November, Union announced she'd been let go from the reality competition series after lodging complaints about a "toxic culture" there; sources told Variety that Union was criticized for her hairstyles being "too black" and detailed an incident in which guest judge Jay Leno made a joke that disparaged Asians. She urged producers to make a report to human resources and was later not asked back.

A-list supporters came to Union's defense on social media, including Ariana Grande and Hamilton creator Lin-Manuel Miranda. Meanwhile, Grey's Anatomy star Ellen Pompeo posted several scathing tweets criticizing NBC. The case eventually became a larger issue about inclusivity in the workplace, and in December, NBC said it was meeting with Union's lawyers.

Discover your new favorite show: Watch This Now!

When asked about lessons NBC has learned from what's happened, and if NBC would make the findings of its investigation public, Telegdy said, "We could always be a better workplace," but he noted that the company is in the middle of a "really serious" investigation involving lawyers and he couldn't say much more. He did say that the network "will put new practices in place, if necessary," after the report is finished.

"I promise you this is being taken very seriously," he added. "We want to always go after the truth."

(Disclosure: TV Guide is owned by CBS Interactive, a division of ViacomCBS.)