A distressed Prince William phoned Princess Diana "upset" over cruel jibes from his Eton classmates following the scandalous publication of topless photos in a UK tabloid.
The 14-year-old William said other boys were teasing him over the size of his mother's breasts.
The revelation, from Conde Nast chairman Nicholas Coleridge, comes ahead of the publication of his memoirs, The Glossy Years.
Writing in the Daily Mail, Coleridge recalled Diana visiting him after the photos were published in the Daily Mirror tabloid.
Coleridge remembers Diana saying: "Nicholas, can I ask you something? Please be truthful. Did you see the photograph of me in the Daily Mirror? The topless one?".