Meghan and Harry levelled allegations of racism against a royal family member during their explosive interview with Oprah Winfrey in March.
The couple refused to reveal the name but confirmed that it was not the Queen.
According to the British media on Friday, Buckingham Palace has declined to comment on the latest claims in a new epilogue to Finding Freedom, an unauthorized biography about Harry and Meghan, according to the British media.
The Duke and Duchess of Sussex have sought to distance themselves from the updated version of the book which has drawn strong criticism from millions of royal fans. Their lawyers in London have also issued a statement on the couple's behalf.
Citing the book, Daily Mail recently reported that the royal couple considered naming the royal family member who had questioned colour of Archie's skin before his birth.