Prince Andrew’s alleged “nasty” comments about Kate Middleton sparked his ongoing feud with his nephew, Prince William, according to a royal biographer.

The disgraced Duke of York, 65, has been estranged from both Prince William and Harry for years — with recent reports suggesting that the Prince of Wales, 43, sees his uncle as a “problem.”

Andrew made several “rude” and “unkind” remarks about the Princess of Wales, according to prominent royal author Andrew Lownie, who details various tidbits about the duke in his latest biography, “Entitled: The Rise and Fall of the House of York .” 4

Lownie added that the alleged remarks came from a place of jealousy, as the duke was envious that Catherine had become a key figure of the Firm following the death of Queen Elizabeth II.

See Full Page