One source said: "The Duchess had no involvement. This has Amanda Thirsk's hands all over it. The Duke is not very quick on his feet so how could Amanda put him up to it.
Amanda was the one who pushed for it. Fifty minutes with anybody on the one subject is going to be difficult. Even Newsnight were flabbergasted."
The source said that the Duchess, who had expressed her support for her ex-husband in an Instagram post on Friday in which she described him as a "giant of a principled man", accepted the interview had been a "car crash".
The Duke and Duchess divorced in 1996 after 10 years of marriage but have remained incredibly close and even live together in Windsor.
A second well-placed source said the Duchess had been abroad last week in Hong Kong, China, Saudi Arabia and then Venice before returning home.
The second source said: "The Duchess was not involved. He [the Duke] has an office and you know who advises him. There is nothing wrong with doing television but it should have been as part of a wider documentary about the work he does. Nobody should be put up in front of a forensic interviewer for 50 minutes on a single topic."
Emily Maitlis, the BBC journalist who conducted the interview, has confirmed that Newsnight was only given the green light on Tuesday and was told Prince Andrew had wanted to get on with it quickly.
The now-notorious four-day visit to New York in 2010 which the Duke insisted was made to say a final "farewell" to Epstein coincided with Prince Andrew securing a loan from the billionaire to help pay off his ex-wife's debts.
The Duchess has suggested that her former husband handled the negotiations with Epstein on her behalf.
In a 2011 interview, she said: "The Duke sorted out my debts and he and his office have been more than marvelous. I cannot state more strongly that I know a terrible, terrible error of judgment was made, my having anything do with Jeffrey Epstein.