Pundits and fellow fighters assumed he had ballooned up by over-eating and under training.
But former trainer Ben Davison insisted the measurements were a brilliant ruse to confuse the American and his corner.
And SunSport has since learned that Fury and his new team of Andy Lee and SugarHill Steward manipulated the weigh-in results by reversing an old boxing trick.
Davison said after the shock weigh in: “Personally, I believe that was a manufactured weight on the scales. I don’t believe he was that heavy.
“I believe that was part of the mind games going on. I know Tyson, I know his body and I do not believe he was that heavy – in fact I know he was not that heavy.
“I believe his morning weight was more in the region of 18st 8lbs, 18st 9lbs. And obviously throughout the day as you’re eating and drinking your weight will increase there.
“But I believe the weight he stopped on the scales at was manufactured weight all part of mind games – which he is the master of.”