The story can be traced back to George Smith, another member of Charles’ household.
According to reports cited by journalist Tom Sykes, Smith made a number of serious allegations in 1996, including claims involving misconduct within the royal household. He also reportedly claimed to have witnessed an incident involving a member of the royal family and a servant.
Diana became involved in Smith’s account, with reports claiming that she recorded what he told her and kept the tape in a locked box at her apartment.
Her former butler, Paul Burrell, later referred to such a tape during his 2002 trial. He claimed he had seen the box, although the recording was never produced publicly.
The allegations surrounding Smith later became part of legal proceedings and generated considerable speculation around Charles and Fawcett.
