Watch: Duchess of Sussex accused of bullying by royal aidesA palace aide who is reported to have made a bullying complaint about the Duchess of Sussex is still working for Prince William and Kate and secured a promotion in their charity.Jason Knauf is reported to have made a complaint about Meghan Markle when she was still working as a senior royal, according to The Times.He is said to have raised concerns that the duchess "was able to bully two PAs out of the household". The complaint was not pursued.The report has emerged days before a special two-hour interview is to be aired on CBS in which Meghan and Harry sit down with Oprah Winfrey to discuss moving back from their roles as senior royals.Knauf worked as a communications secretary to Prince Harry and Meghan and Prince William and Kate for four years before the Sussexes decided to split their royal household from the Cambridges.Jason Knauf is said to have made a bullying complaint about the duchess. (PA/Getty)Since then Knauf has worked for the Duke and Duchess of Cambridge, and went from being their senior adviser to becoming chief executive officer of the Royal Foundation, which their charitable work is conducted through.The Times alleges that the complaint was made by Knauf in October 2018 and a source said Prince Harry asked him not to pursue it.The duchess said she was "saddened" by the report on Wednesday.In a letter sent by lawyers to The Times, Meghan said allegations were a "smear campaign" based on "misinformation".Jason Knauf on a visit to Leicester City FC's stadium to pay tribute to people killed in a helicopter crash in 2018. He is now in charge of the Royal Foundation. (Max Mumby/Indigo/Getty Images)Read more: How can I watch Harry and Meghan's Oprah interview in the UK?Knauf was once an important figure to the duchess. She consulted him in summer 2018 about a letter she wrote to her father Thomas Markle Snr, it recently emerged in court.Knauf has been named repeatedly in the case between Meghan and Associated Newspapers Ltd, who she sued after they printed extracts of the letter to Markle Snr in the Mail On Sunday and MailOnline.He is said to have helped her with "general ideas" about the letter, which could lead to him having a copyright claim in its formation.Knauf was also the adviser who wrote the statement to the press that condemned the "wave of abuse and harassment" Meghan faced when she was Prince Harry's girlfriend.He attended their wedding in May 2018.In 2019, Knauf was promoted to OCE of the Royal Foundation, when Natalie Campbell moved with the Duke and Duchess of Sussex to their new household and charity.According to Vanity Fair, William and Kate were thrilled to promote Knauf and he was described as "their guy".Watch: Prince Harry opens up about Princess Diana's death in exclusive interview with Oprah WinfreyRead more: What Oprah Winfrey has said about her friends Harry and MeghanKensington Palace released a statement which added: "We are pleased that Jason has been appointed as CEO and very much look forward to working with him in his new role."In a legal letter to The Times, Harry and Meghan said: "Lets 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."Its 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.A spokesman for the couple told Yahoo News UK: "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. "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."Quiz: Can you name the year of these royal milestones?Harry and Meghan's interview with Winfrey, a friend of theirs, is due to air on CBS in the US on 7 March.The show was originally billed as a 90-minute special but has been extended to two hours.In a preview of the programme, Winfrey says no subject was off-limits, while Harry says he feared history would "repeat itself", referring to the way his mother Princess Diana died in 1997.The programme will be shown in the UK on ITV on 8 March.Watch: Will Meghan Markle be in The Crown?