But, according to an insider, these accusations could just be the tip of the iceberg, and the 39-year-old "should be prepared" for others to come forward.
“The Palace did everything they could to cover up the complaints that were made about Meghan, but that ended the moment she sat down with Oprah [Winfrey],” a source told The Royal Observer. “There are many different sides to a story. Meghan has decided to tell her side and now should be prepared for others to tell theirs.
"Don’t expect the Queen or senior members of the family to run and do interviews with the British Oprah," the source continued. "They had people to do their dirty work, while they keep their hands clean. You have to remember the royals are not just a family, they are one of the oldest businesses in the world with PR teams and massive connections. Meghan might have Oprah, but the Queen has everyone else.”
According to the new report by UK Times, the complaint against the former Suits actress was made in October 2018 by the couple's former communications secretary, Jason Knauf. At the time, Knauf claimed Markle "drove two personal assistants out of the household and was undermining the confidence of a third staff member."
Knauf reportedly sent an email to the Duke of Cambridge's private secretary, Simon Case, who is now the cabinet secretary, after conversations with Samantha Carruthers, the head of HR.
According to Daily Mail, the email read: "I am very concerned the duchess was able to bully two PAs out of the household in the past year. The treatment of X was totally unacceptable. The duchess seems intent on always having someone in her sights. She is bullying Y and seeking to undermine her confidence. We have had report after report from people who have witnessed unacceptable behavior towards Y."
After learning of Knauf's complaint, Prince Harry allegedly insisted on meeting with the couple's former communications secretary and begged him not to pursue the complaint. Lawyers for the the couple denied the meeting ever took place, The Times reported.
A spokesperson for the Duke and Duchess of Sussex, who are expecting their second child later this year, slammed the accusations.
“Let’s just call this what it is — a calculated smear campaign based on misleading and harmful misinformation,” a spokesperson for the Duke and Duchess of Sussex said in a statement, while noting: “It’s no coincidence that distorted several-year-old accusations aimed at undermining The Duchess are being briefed to the British media shortly before she and The Duke are due to speak openly and honestly about their experience of recent years,” referring to the couple's upcoming special with Winfrey.
"The Duchess is saddened by this latest attack on her character, particularly as someone who has been the target of bullying herself and is deeply committed to supporting those who have experienced pain and trauma," the statement added. "She is determined to continue her work building compassion around the world and will keep striving to set an example for doing what is right and doing what is good."
Buckingham Palace later issued a statement that it will look into the matter.
"We are clearly very concerned about allegations in The Times following claims made by former staff of The Duke and Duchess of Sussex," the statement reads. "Accordingly our HR team will look into the circumstances outlined in the article. Members of staff involved at the time, including those who have left the Household, will be invited to participate to see if lessons can be learned.
"The Royal Household has had a Dignity at Work policy in place for a number of years and does not and will not tolerate bullying or harassment in the workplace," the statement added.
Markle's alleged treatment to her royal staffers comes as she and her 36-year-old husband get ready to air their primetime 90-minute sit down with Winfrey. After years of staying quiet, the duo will finally have the chance to talk about their decision to leave their royal life behind, the intense public pressure they endured and more.
"I just want to make it clear to everybody there is no subject that's off-limits," the legendary T.V. host said in a sneak peek of the interview before she asked: "Were you silent or were you silenced?"
However, the debut of the special also comes as Harry's grandfather Prince Philip battles a pre-existing heart condition and infection in the hospital. As OK! previously reported, many worry that this may be the end of the road for the Duke of Edinburgh, 99, as royal commentators beg Harry and and his wife to hold off on releasing the interview until Philip's health scare is taken care of.