Buckingham Palace has hired an external law firm to investigate claims that Meghan, the Duchess of Sussex, bullied royal staff, CNN reported.
The Palace initially said it would investigate after a British media report earlier this month cited unnamed royal aides as saying a complaint had been made against Meghan in 2018.
A spokesman for Buckingham Palace said on Monday: "Our commitment to look into the circumstances around allegations from former staff of The Duke and Duchess of Sussex is being taken forward but we will not be providing a public commentary on it."
CNN was not told which firm would be investigating the claims.
The move comes as the Palace faces a crisis over the allegations made by Prince Harry and Meghan in their explosive interview with Oprah Winfrey.
Harry and Meghan did not comment on Monday, but a spokesperson for the couple previously dismissed bullying accusations reported by The Times newspaper as "defamatory."
"Let's just call this what it is -- a calculated smear campaign based on misleading and harmful misinformation. We are disappointed to see this defamatory portrayal of The Duchess of Sussex given credibility by a media outlet," the Sussexes' spokesperson said.
The war of words between the two camps erupted shortly before the airing of Meghan and Harry's discussion with Winfrey, in which the couple lifted the lid on the difficulties of their lives as royals and made a series of damning allegations against the family.
Most strikingly, Meghan said that there were "concerns and conversations" about the skin color of their baby, Archie, and "what that would mean." Buckingham Palace later said the allegation of racism was concerning but that it would be addressed by the family privately.