Tyson Fury and his cousin Hughie are set to claim they failed drugs tests after eating vast amounts of contaminated offal, The Daily Mail reports.
Charges against the cousins will be heard by the United Kingdom's National Anti-Doping Panel next month, with the Fury camp thought to be confident of avoiding bans.
The pair will argue they unwittingly tested positive for a banned steroid because they eat a whole boar, including its internal organs and entrails, between them each week.
The Furys - Hughie, 22, and Tyson, 28 - strenuously deny using drugs to boost performance. Their legal team will argue that eating the liver of an animal that has been fed steroids to enhance its growth can leave traceable amounts in a human body. A farmer is set to testify that the Furys buy a boar from him each week.
The case has been protracted, with both heavyweight boxers provisionally suspended on June 24 last year after failing tests by UK Anti-Doping.