Jason Knauf began working for the Cambridges after an alleged row with Meghan Markle
Kate Middleton and Prince William's charity boss has stepped down from his role ahead of a "planned international relocation".
Jason Knauf will stand down as chief executive of The Royal Foundation at the end of the year, a statement announced on Wednesday (12 May).
Knauf was the royal adviser who first reported Meghan Markle for alleged bullying in 2018, according to the Times.
He moved to work with the Cambridges in 2019, after the Sussexes quit the royal family.
Knauf is alleged to have made a complaint about Markle's behaviour towards other aides, which is said to have forced Prince Harry to step in.
Reports say the duchess "drove two personal assistants out of the household", while "undermining the confidence of a third staff member".
Markle denies the claims and her team issued a stern statement in the wake of the accusations, describing them as a "calculated smear campaign based on misleading and harmful misinformation".
A spokesman for the couple also said Harry would not interfere in staff matters
Knauf joined the communications team at Kensington Palace in 2015 before moving into his role with the foundation in 2019.
In a joint statement on his departure, the Duke and Duchess of Cambridge said: "Jason has been an integral part of our team since 2015.
"We are immensely grateful for his hard work and commitment, both at The Royal Foundation and previously as our communications secretary.
"Since taking over as chief executive, Jason has driven positive change, making our vision for our charitable work and the causes that matter most to us a reality.
"We are sad to see him go but wish him all the very best in his future career.
"We look forward to launching the recruitment search shortly and welcoming a new chief executive later on this year."
Knauf added: "Working with The Duke and Duchess of Cambridge has been the privilege of my career.
"I will always be grateful for the opportunity I have had to support their leadership in the UK and internationally.
"The months ahead will be the busiest time in the Foundation’s history with the first awards for The Earthshot Prize and more progress on our early childhood work.
"We have a lot to do with our amazing team and all of our partners."
A statement added that Knauf "will remain in post until the end of 2021 before a planned international relocation that has necessitated his decision to stand down".