Royal biographer Omid Scobie and his X followers have been described as "f*****g nuts" in Mike Tindall's new book.
Mike has co-written 'The Good, the Bad & the Rugby - Unleashed' with former England rugby player, James Haskell. It is set to be released next week, October 24.
James branded Omid - who co-wrote 'Finding Freedom' in 2020 - as "a very odd bloke".
He added: "We all know that American royal fans are f*****g nuts, especially Scobieites".
It comes after Omid slammed the former rugby professional Mike and accused him of "cashing in" on the Royal Family by appearing on I’m A Celebrity, Get Me Out of Here.
In the book, Mike wrote: "I don’t even have access to my Twitter. I just [get] tagged in by anyone who’s talking about anything. It’s so random, what I have to sift through."
Mike and Zara are said to have a close bond with Prince and Princess of Wales - with their children even known to be close.
Zara and Mike welcomed their first child, Mia, in 2014. They also have two younger children, Lena, six, and Lucas, three.