Joshua puts his WBA and IBF heavyweight titles on the line against WBO champion Joseph Parker in Cardiff on March 31.

The Kiwi claimed Joshua is “the king of steroids” at the weekend before the £25m bout was finally sealed, and although he backtracked yesterday when face-to-face with the unbeaten Briton, Joshua claims no man on the planet can beat him as he is too mean and totally clean.

“It will take more than a human to stop me from where I am destined to be,” said Joshua. “In terms of you, using it as a PR stunt and the rumours you have heard, they are fake news.

“Three times I’ve been hurt or stopped. What I have learned from those adversities and storms, it will take more than any human to stop me from this journey.

“I know my records are clean every time I’m tested – that’s why I don’t bite at it.

“If I’m not clean you’ll find out in this fight. If I haven’t been clean for my fights you’ll see me struggle against Parker because anything I’ve taken would be out of my system.

“You’ll find out throughout this fight whether I’m actually superhuman or if I have something pushing on this superhuman power he thinks I have.

“It’s a shame that people get caught up with that sort of thing.”

Parker, who will fly from London to Las Vegas today to begin his training camp, said at the weekend: “They call me the king of pies, but I call him the king of steroids.

“If you’re that big and that muscly, there’s something wrong. I have heard the word, I have looked at him and I have seen. 

“I am not accusing him of using steroids, but I am saying it is a possibility. There are a lot of ways you can dodge drug-testing.”

But yesterday he had completely changed his tune.

“They accused me of being the king of pies, so that was the first thing that came into my head,” he said.

“It’s one of those things you say without thinking and it wasn’t the best thing to say. We should just leave it in the past.”

Joshua has won all 20 of his professional bouts inside the distance and showed respect to his next opponent, who is unbeaten in his 24-fight career.

The 28-year-old added: “I’ll be in peak physical condition but I’m making sure my mind is in the right place as well, at all times.

“I’m looking forward to embracing the challenge, not just from a physical stand point but the mental challenge that will come from this fight as well.”

Parker was in no doubt the upcoming clash would be the most difficult of his career, but he anticipates he will be taking three major world titles back to New Zealand.

“It’s an exciting time to be a heavyweight,” he said. “This is going to be the hardest camp and most work as I have a big challenge in front of me in Joshua.

“I’ve watched him for a long time. I know his strengths, he knows mine. I know his weaknesses and he thinks he knows my weaknesses.

“I can’t wait to have this fight. I can’t wait to put on a great performance, hopefully I will catch him on the chin and knock him out.”