Speaking on the upcoming ITV documentary, Harry & William: What Went Wrong?, Mr Scobie alleged William’s staff exacerbated the rift between the brothers.
Mr Scobie, told the documentary: “I would say that it was no coincidence that it was shortly after that aired, even the next day, there were source quotes that came from a senior aide at Kensington Palace saying that William was worried about his brother’s mental health.
“That fed off such an ugly thing for Harry and it did not go unnoticed.
“Now whether William directed that or not, no one will ever know, but it came from his household that he is the boss of.”
Mr Scobie’s allegations have not yet been reinforced with evidence.
The 2019 interview with Tom Bradby came at the end of Prince Harry and Meghan Markle’s tour of South Africa.
During the interview, Meghan also revealed she was “surviving, not thriving” and suggested the Royal Family had not been mindful of her mental health.
Experts took the interview as confirmation that the once close siblings had drifted apart.
The ITV documentary is set to get to the bottom of the royal rift and “explore allegations that many of the negative stories about Harry and Meghan were the result of briefings from within the Palace,” through a series of interviews with royal insiders.
READ MORE: Prince Harry rift still ‘too raw’ for William and other royals
Mr Scobie’s allegations come just days following Prince William and Harry’s meeting for the unveiling of the Princess Diana statue at Kensington Palace.
Experts predicted the meeting, on what would have been the late Princess of Wales’ 60th birthday, would be an opportunity to begin healing the rift.
However, they have suggested Harry’s short return trip was not long enough to enact any meaningful change.
Harry & William: What Went Wrong? will air on ITV Sunday night from 9-10pm.
Express.co.uk has reached out to Kensington Palace for comment.