In 1994, six months after his retirement from the military, Anna Pasternak published the book Princess in Love.
Hewitt was a major source, and it alleged that Hewitt had had a five-year affair with Princess Diana, Diana confirmed the affair in her 1995 Panorama interview.
While James has always denied the claims, he was recently asked point-blank about the rumor during an interview with Australia's Sunday Night, to which he replied, "No, I'm not.
As the 20th anniversary of Princess Diana's death approaches, rumors still remain about the life and death of Lady Di.
"It wasn't for me to moralize on this.""I didn't really have a view on it openly or inwardly, you know. "I was there for one specific reason, I would never let her down.".
"I adored him," Diana famously admitted during her BBC1 Panorama interview in 1995.
He endeared himself to her kids, who he taught to ride and then went for the old helpless-bloke routine to cement the relationship, Diana admitting that she had dressed Hewitt "from head to foot." Undoubtedly.
By all accounts the couple enjoyed many an illicit liaison from about 1991, a period when Charles and Diana's relationship had hit new lows.
As with Gilbey, Hewitt's chances of landing Diana on a long term deal were always doomed by the fact the Princess was simply not up to committing herself.
At the time, rumors also swirled that Prince Charles was seeing his now-wife, Camilla Parker Bowles. As he recalled, their romance soon blossomed with secret rendezvous on his farm filled with home-cooked dinners and laughing.
While many have alleged James and Harry share a physical resemblance, the former British officer has not only denied for years that the allegations are false, but also that he met the princess when her second son was already a toddler. "It's a gradual period and then, you know, suddenly you can't get enough of each other or see each other as much as you want," he said.
Diana herself said she was "absolutely devastated" when she discovered he'd spilled the beans on their relationship for hard cash and cut him out of her life.
What, then, did this cad have going for him to attract her in the first place?