Prince Harry's wife Meghan has accused Buckingham Palace of "perpetuating falsehoods" about her and her spouse, saying the royal couple would not be silent in telling their story.

Meghan, the Duchess of Sussex, made the comments to American talk show host Oprah Winfrey in an interview about why they quit their royal roles that is due to be broadcast on U.S. television on Sunday.

An advance excerpt of the interview was released on Wednesday, hours after Buckingham Palace said it was "very concerned" about reports in the Times newspaper that assistants working for Meghan two years ago had been bullied by her.