Now it comes. That rare flashback to gangland days. A startling glimpse into the street fighter before the world champion.

‘If they f*** me, they won’t be waking up next morning.’

Anthony Joshua is talking about those to whom he delegates the running of his business empire.

Anthony Joshua defends his heavyweight belts against Oleksandr Usyk on Saturday

The British champion has amassed a huge fortune but he wants to become a boxing billionaire

‘What I’ve done is put a trusted team around me. So far, so good. They’re still breathing. I’m not going to jail. We’re happy. Everything’s fine.’

There it is. A stark warning to AJ’s associates that if they cook the books they will be the ones who end up as toast.

A timely reminder to Oleksandr Usyk, the former undisputed world cruiserweight champion against whom he defends his titles this Saturday — and Tyson Fury, with whom he hopes to dispute the undisputed world heavyweight championship next spring — of the capacity for explosive violence which lies beneath the engaging smile and the courteous charm.

The gutters of boxing history are littered with the human debris of heroes whose hard earnings, be they great or small, have been plundered or squandered.

Having made it clear beyond all doubt what will happen to anyone who plays fast and loose with his fortune and his future, Joshua throws back his head and laughs.

Do not be deceived that he is joking. There is too much at stake. More than a hundred million at the last count. And rising. Fast. More than doubling once Joshua and Fury finally get it on. Twice. Maybe ever upwards toward becoming the first boxing billionaire of his stated ambition.

Usyk wants to take Joshua’s belts and boost his own earning power, but AJ is set up for security

Tyson Fury is next on the Watford-born fighter’s wish list, hoping to become undisputed

The glittering football stadiums in London — Tottenham Hotspur this weekend, more often Wembley — offer richer pickings by far than a little drugs-meddling in Watford alleyways.

So do all the sponsors who have flocked of late to the candle of his fame: Jaguar Land Rover, Under Armour, JD Sports, Beats, Hugo Boss, William Hill, Lucozade, British Airways, Sky, DAZN among them.

Then there are his own companies which will continue to engage him in the sport he loves after he hangs up the gloves: AJ Boxing and Commerce which includes his foray into fighter management, the state of the art BAR Gym, Sparta Promotions who are beginning to put on fight events. Bringing in between them all £11million a year.

Good for him. Better by light-years than ending up destitute like the great, late Joe Frazier in a tumbledown shack by an old railroad track in Philadelphia. Wise of him to know that his prowess in the ring is the rock without which the entire edifice would crumble.

Having assembled his army of city wise-guys and put that gun to their heads, Joshua says: ‘What I have to do now is focus entirely on my boxing.

Joshua has attracted a mountain of brands including JD, and the likes of Sky and Beats

‘When I came out of the amateurs as Olympic champion it was a lot easier for me inside the ring than the battle outside the ring. So, early on, I spent a lot of time reading the business climate.

‘Boxing is an unforgiving world when it comes to making the right decisions. At the start it was so difficult. But I came to understand the power of the corporate companies, the phenomenal power of big brands and what they can do for boxing.

‘I studied the history. A century ago there was a world heavyweight champion called (Gentleman) Jim Corbett who knew the importance of self-promotion. Then came Muhammad Ali who was The Greatest at self-promotion as well as boxing.

‘Most fighters today know we have to sell ourselves. The talking is as important as the fighting. Business matters.’

But there is a reason why Joshua has been less visible than usual in the media of late. He explains: ‘For me the time has come to stand back from all that and focus only on the fighting and the winning.

While Joshua was making his meteoric rise through the divisions he was studying business

‘I also know that what matters most of all to the public is to excite. To give them something back for what it costs to come out to watch me. To give crowds like the 60,000 who will be in Tottenham’s stadium this Saturday value for their ticket money.

‘That’s why you very rarely see me in a boring fight. But to go on and on doing that as the level of championship fighting keeps rising higher and higher, I must give total concentration without distraction.

‘When it comes to a brilliant technical boxer like Usyk or a big physical threat such as Fury, I know I must keep getting better and better. But to improve even 1.5 or two per cent before each fight demands six to eight months of hard work and total dedication to my craft and to my supporters.

‘I must suffer in training so that they can be sure I will be as good as I can possibly be.’

This time around that has involved what he calls ‘deep practice of the feet placement, body positioning and angles of the punches which it takes to smother a clever southpaw like Usyk’.

Joshua have been working hard in the gym and making less noise surrounding this fight

He adds: ‘This will not just be about the bigger man going for the quick knock-out.’

Joshua regards Usyk as ‘second only to Wladimir Klitschko of my opponents’ and is pleased to meet that challenge. He says: ‘For up-and-coming fighters now it’s often more about the talking to build up the money.

‘But back in the day the only way great boxers got the rewards they deserved was by fighting each other. And when I look back I admire how Sugar Ray Leonard, Marvin Hagler, Roberto Duran and Tommy Hearns built the legend of the Fantastic Four by doing just that.

‘I would like to be the same. I want to box more often than two or three times a year, although that’s not been possible during the pandemic.

‘It’s a different era now but I see myself as a throwback fighter. Like those guys, I want to be known as a man who took on all challenges. To build my lineage.’

How long will he carry on in pursuit of that legacy?

‘A good few years yet,’ he says, ‘now that I can keep my mind only on the boxing. I turn 32 next month so the question is how long will I go on after 36? Maybe now, having taken care of business, the full shoot to 40. However long it takes. Long as I can. I love boxing. It’s what I do best.

Joshua wants to fight more, his last bout coming back in December 2020, beating Kubrat Pulev

‘Then it will be up to you guys, you sportswriters, not me, to decide my place in heavyweight history — whether or not I achieve greatness. I am fighting for that position. I am pushing for it, I am living it, I am working as hard as I can for it.’

He invokes the memory of Larry Holmes, whose greatness was largely overlooked because he lived so long in the shadows as Ali’s sparring partner.

Joshua says: ‘Holmes didn’t get the credit he deserved. I know who I am but if for any reason the full recognition doesn’t happen, I won’t be fully satisfied with my career.

‘At the very least I want my son to grow up able to say to his mates, “My dad fought everyone, what did your dad do?” I want him to know I was a serious heavyweight champion respected for fighting them all.’

To that end, he adds: ‘Usyk and Fury will be very welcome on my resume.’

And whatever else, this is one street fighter heading for the Fortune 500, not the scrapheap.