Tyson Fury’s father was injured in a fracas with members of Oleksandr Usyk’s camp as the build-up to Saturday’s undisputed world heavyweight contest got under way in Riyadh, Saudi Arabia.
John Fury was left with blood running from a cut on his forehead as security separated the rival entourages.
The incident took place at a hotel where Monday’s media activity was taking place.
Videos posted on social media appeared to show John Fury, 59, being restrained as members of Usyk’s camp chanted their fighter’s name.
WBC champion Fury and Ukraine’s Usyk, who holds the WBA, IBF and WBO belts, will fight at the Kingdom Arena with the winner becoming the first undisputed heavyweight champion of the four-belt era.
Lennox Lewis was the last undisputed champion, in 1999, when the WBC champion won the WBA and IBF titles from Evander Holyfield.
