The 36-year-old heavyweight’s clip of him grappling the animal went viral and he admitted people didn’t believe the footage was real, but he’s now explained what led to the “crazy” altercation.

He told Boxing News magazine: “It’s kind of crazy. People think it’s not a real bear.

“For me, it was kind of a challenge, because one guy told me, ‘My friend, do you want to wrestle a bear?’

“I said, ‘OK, let’s do it. Let’s try.’

“When I’d just arrived at this place in the forest, this bear was sitting and made a crazy noise. It’s so scary brother, so scary.”

There were times during the encounter when the Russian feared he would “die”, particularly when he was bitten by the bear.

He added: “You feel with this animal, even if you have a gun, you can do nothing because he’ll kill you right away, and for me it was like a challenge to test myself.

“Of course, you feel fear. It’s like in boxing – you feel the fear until you get in the ring, you go to die or to win.

“What happened to me, I went for him and he bit me.

“I said, ‘OK, I die or I do wrestling.’ It’s like when you go for a fight.”