Ronald Zupancic, a security specialist for Travolta, said he was the one who told his boss of the alleged demand in the days following his autistic son's death in January.
He said ambulance driver Tarino Lightbourne contacted Travolta's attorneys through a lawyer, former Bahamas Senator Pleasant Bridgewater, who is also facing extortion charges.
"He had a document that he contended was incriminating to Travolta," Zupancic told the jury.
The document, which Travolta signed, would have cleared the ambulance driver of liability if the family refused to send 16-year-old Jett Travolta to the hospital. The actor testified last week that he initially wanted his son flown to Florida for treatment after a seizure on January 2 that resulted in Jett's death.
But Jett was treated in the Bahamas, and it is unclear why the defendants allegedly believed Travolta would pay to keep the document private.
The trial began September 21 and is expected to last several weeks. Travolta is expected to give further testimony later in the trial.
