Two-time world heavyweight champion Anthony Joshua is set to face Daniel Dubois or the IBF belt in an all-British showdown at Wembley Stadium in September.

Eddie Hearn said any bottled substance that Anthony Joshua consumes is tested beforehand to avoid any attempt of the British boxer ingesting banned substances through surreptitious means.

Joshua is bidding to become a three-time world heavyweight champion on September 21 as he faces Daniel Dubois for the IBF belt in an all-British showdown at Wembley Stadium.

Anthony Joshua will face Daniel Dubois in September.

The fight will arrive almost three years to the day since Joshua relinquished his WBO, WBA, IBO and IBF titles to Oleksandr Usyk, and two years since his last world title fight after losing to the Ukrainian in a rematch.

Joshua has won all four of his fights since to galvanise his shot at title redemption.

And according to Hearn, he and his team go to great lengths to avoid any threat to the sanctity of the two-time world heavyweight champion boxing reputation amid a slew of doping scandals involving high-profile boxers in recent years, including two of Joshua’s opponents last year.

Joshua was forced to fight Robert Helenius after Dillian Whyte failed a drugs test, knocking the card down from a pay-per-view bout to a standard DAZN fight.

But the controversy only escalated after Finn also tested positive following Joshua’s seventh-round knockout. Joshua, meanwhile, returned negative tests for his Voluntary Anti-Doping Association (Vada) tests.

Both men protested their innocence. And while Helenius was handed a two-year doping ban for violating anti-doping rules, Whyte was cleared to resume his boxing career after it came to light that a contaminated substance resulted in the positive drug test ahead of his battle with Joshua.

Joshua will fight Dubois in September.

And boxing promoter Hearn believes the threat of contamination through unintentional or even devious means is so great to boxers at elite-level, that the 45-year-old has claimed he tests every bottle that comes within touching distance of Joshua.

“I think 20% of failed drugs tests are legitimately fighters that are unlucky or have unknowingly taken a substance,” Heard told GRM Daily’s Thoughts In A Culli. “I think 80% of people cheat. And establishing what’s what is very difficult to do.

“Because fighters are never going to take illegal substances themselves. Someone will come up to them and say, we need to improve your strength and what we can do is take some of this. And maybe they won’t even tell them it’s a banned substance. But a lot of the time people are genuinely cheating.

“And we’re talking about testing to minute trace levels that would be in your blood. And in Mexico, there is a genuine thing where some meat contains testosterone. And fighters test positive for that. Things like eggs, you don’t know what people are putting in animals.

Anthony Joshua knocks down Robert Helenius

He added: “Whenever I go to a restaurant with AJ, I’m looking at the food thinking, because there’s some horrible —s out there, you put something in that food and your career is over. And imagine, everything that you built, all because of one evil individual, comes crumbling down.

“Here’s another example. After a tough fight, you might get in the ring and someone – either from the other team or wherever – and they’ll come up to you and offer something to drink. What’s in that? Do you know what I mean? I’m not saying that there is anything in there, but there could be.

“So at the top level, like AJ, every bottle is tested. Every bottle is sealed. Nothing comes in the changing room. You have to, because you’re correcting your career, your brand, your reputation. The worst thing in the world is testing positive for having not knowingly taken a substance. Then you’re called a cheat for the rest of your life despite never having done it.

“I’m paranoid in that world because I know what people are like.”