Aristotle Onassis and Jackie Kennedy

In the late 1960s, JFK's widow had a secret romance with the Greek shipping magnate who was then the world's richest man. Witness speaks to Nico Mastorakis, a Greek journalist who visited Onassis' yacht in disguise in order to confirm the affair.

(Photo: Jackie Kennedy with Aristotle Onassis in 1968. Credit: David Cairns/Getty Images).