Tyson Fury is believed to be sparring with convicted killer Ty Mitchell ahead of his bout with Anthony Joshua.
Fury is set to take on fellow Brit AJ in a battle for the undisputed heavyweight champion of the world this summer.
Contracts are signed though a date and venue is still to be decided, but the Gypsy King is ensuring he stays in peak condition.
According to The Sun, Mitchell posted footage of himself and Fury sparring in Morecambe last week.
Mitchell was sentenced to seven years in prison after being found guilty of manslaughter.
He killed uni student Jagdip Randhawa, 19, with a single punch in October 2011.
Mitchell will remain on licence until December this year with the family of his victim declining to comment to The Sun.
Mitchell had been in five professional boxing bouts before his conviction, winning three and losing the other two.
He has been fighting in white collar bouts with the family of University of Leeds student Randhawa having previously criticised the decision.
Mr Randhawa’s sister Majinder Randhawa said: “We are concerned that he is honing these skills again and he will go and hurt somebody again and this is all preventable.
“Why on earth would we let him walk around on the street with these skills when he doesn’t have the control that goes with being a boxer?
“Why would you not mitigate the risk to the public if you can? We don’t want this to happen to another family. We are never going to get over this.”
While Mitchell’s father, Clifton Mitchell, had said the fatal punch was a freak accident.
He added: “He is not a hooligan, he was just a kid when it happened…boxing is his only trade.
“My son will fight again.”