Her account emerges amid renewed scrutiny of Harry following the dismissal of his legal case against Associated Newspapers Limited, the publisher of the Daily Mail and The Mail on Sunday.
Harry, alongside figures including Sir Elton John, David Furnish, Elizabeth Hurley, Sadie Frost, Baroness Doreen Lawrence, and Sir Simon Hughes, had alleged unlawful information gathering.
Griffiths claimed, “From his pocket, he removed a small white pill.”
She added: “Then he held it up to my face, popped it onto my tongue, and said with a smile, ‘Now I know I can trust you!’… take that white pill he’d so brazenly stuck in my mouth.”
“It was almost certainly paracetamol, rather than something more sinister. But I couldn’t be entirely sure,” Griffiths recalled.
Griffiths said the moment came early in what she described as a budding friendship with Harry, and suggested the gesture was intended as a prank to “kick start” their relationship.
The anecdote has gained traction as Harry faces ongoing criticism following his failed legal action.