Astonishingly the Duchess of York has been working on the pilot programme and her training course at Broadcasting House for nearly four months without being noticed by the journalists there.
The Duchess has already interviewed celebrities as diverse as Pavarotti, Joan Collins and the head barman at the Savoy hotel. She has made some of the recordings at Broadcasting House with BBC executives from director- general John Birt downwards informed and sworn to secrecy. The interview with Pavarotti was taking place in Italy yesterday.
The Duchess has not been paid a fee, but she has been given a BBC training course and assigned a top ranking producer, Sally Feldman, the former editor of Woman's Hour. She is also likely to get a share of the profits on the sale of the programmes abroad.
However, while the series will be sold abroad it will not initially be broadcast in the UK. This is understood to be at the request of the Duchess.
The Queen has not been told of the venture.
BBC sources were keen to stress that none of the exercise has been funded by the licence fee. It is all being funded by BBC Worldwide, the corporation's international arm, which plans to sell the shows abroad.
It is already negotiating to sell the Fergie chat shows to America, the first time that a BBC radio chat show series will have been sold to the US. One BBC insider said: "We needed to raise our profile in the US radio market.
"It's a 12.8 bn dollar business with 10,000 radio stations. We wanted to enter the chat show market and we needed a really sexy chat show host, a really interesting and unusual type. We approached the Duchess about it.
"She wants to take life seriously, and she takes the BBC very seriously. She has proved to be a rivetting chat show host."
However, while the weekly series will be sold widely abroad, there are no plans at the moment to broadcast it in Britain.
John Willan, director of Radio International, said yesterday: "We are at an early stage but so far the signs are that she has a natural talent for radio."