They were recorded with leading historian Arthur M Schlesinger Jr within months of the assassination on November 22, 1963, and have been sealed in a vault at the Kennedy Library in Boston until now.
Jackie O, as the world came to know her after she married Greek shipping tycoon Aristotle Onassis five years later, ordered that the tapes should not be revealed until 50 years after her death. But although she died from cancer aged 64 in May 1994, her daughter, Caroline Kennedy, has agreed to release them to US television network giant ABC.
A spokesman there confirmed that the tapes' "explosive" contents will be aired in a two-hour TV special, although he refused to divulge further details. The Sunday Express has, however, learned that Jackie:
- Believed that gunman Lee Harvey Oswald was merely "a patsy" in the murder of JFK and was working for a sinister cabal led by a group of Texas tycoons.
- Suspected her husband was having an affair with a 19-year-old White House intern whose underwear she found in their bedroom.
- Wrote-off most of JFK's extra-marital dalliances as "Jack's meaningless flings".
- Plunged into affairs herself with Hollywood star William Holden and Fiat car mogul Gianni Agnelli in revenge for his serial philandering.
Their efforts to strengthen their marriage were confirmed by Kennedy author and historian Ed Klein, who said: "Jackie regarded the pretty young things in the White House as superficial flings for Jack.
"Still, she did retaliate by having her own affairs. There was a period during which she was delighted to be able to annoy her husband with her own illicit romances."
It is believed that Caroline, 53, agreed to release the tapes to ABC after pleading with the network to drop an embarrassing, £15million mini-series about the Kennedys that was due to air on its History Channel.
The series was eventually broadcast in America earlier this year, against Caroline's wishes, on the independent Reelz cable network and in many other countries, including Britain.
The senior source said: "The Jackie tapes are, in effect, Caroline's trade-off for ABC dropping The Kennedys series."
On the assassination, a second source said Jackie believed gunman Lee Harvey Oswald was "part of a much larger conspiracy." She became convinced that Vice-President Lyndon Johnson, JFK's successor, and a cabal of Texas tycoons were involved.
"Those businessmen expected that LBJ would give them more favourable treatment in Vietnam War contracts and oil policies.
"There is no doubt that Jackie wanted the truth to come out, but feared that she and her children, Caroline and John Jr, might also be marked for death by the conspirators."
happened.