No more Mr Nice Guy! From leaked WhatsApp messages to threatening his opponent with a chair - how Anthony Joshua has become boxing's bad boy ahead of Daniel Dubois bout

Anthony Joshua will make his return to the boxing ring towards the end of the year when he takes on rival Daniel Dubois in a highly-anticipated bout for the title. 

The two heavyweights will face-off for the IBF heavyweight belt on September 21st, after Oleksandr Usyk vacated the title last month.

Usyk - who initially claimed the IBF belt following his victory over AJ - had been under pressure to face his overdue mandatory challenger Filip Hrgovic however, Dubois stopped the Croat to put himself into the picture.

Now, 'AJ' will take on Dubois at Wembley and, ahead of the bout, has appeared far more disruptive and antagonistic than we have previously seen in his career.

Here, Mail Sport looks at how the British star has slowly become boxing's bad boy ahead of the bout. 

At the end of June, it was officially confirmed that Joshua will take on Dubois in a bout for the IBF heavyweight belt.

The fight at Wembley Stadium is expected to be part what promises to be a highly stacked Riyadh Season card.

Dubois's victory over Hrgovic at the start of June saw the Briton claim the IBF 'interim' belt. He was upgraded to the IBF world champion after Usyk was officially stripped of his belt on June 26.   

The chain of events ultimately set up an all-British showdown with AJ at Wembley, which was announced on the same date. 

As part of the promotion for the fight, Joshua and Dubois sat down face-to-face and it didn't take long for them to come to blows. 

Tensions rose when Dubois told Joshua that he was more than ready to 'go now' if he 'wants to swing'.

'Shut up, relax,' Joshua responded. 'I'll throw this f***ing chair across your face. Don't disrespect me.'

Dubois attempted to remain calm, saying: 'You can't intimidate me, who do you think you are?'

That comment got Joshua out of his seat with the pair having to be separated by security as Frank Warren and Eddie Hearn watched on.  

'Daniel don't disrespect me or I'll put this f***ing chair through your face,' Joshua continued. 

'Warn this little boy not to disrespect me. I don't take disrespect lightly you know. Don't sit on the table telling me we can go now, telling me this and that.

Promoter Warren said: 'This was serious. We don't need any stunts to sell this fight.'

'Wembley Stadium will be sold out in no time. Who won't want to see two British giants with massive punching power go at each other. It's what heavyweight boxing is all about.

'Daniel is really up for this fight already. And the big pressure is on Joshua at this later stage of his career.'

It seems as though this confrontation may have been the first sign of Joshua's bad boy persona as, shortly after, Carl Froch revealed the details of a heated WhatsApp spat between them.

It came after Joshua was asked to sum up Froch in one word and opted for 'pr***'. 

Posting screenshots alleged to be from a private conversation with Joshua after the press conference for that fight, 'the Cobra' tore into AJ on the latest episode of 'Froch on Fighting'.

'So he's called me a 'pr***' and I've gone back to him saying "who are you f***ing calling a pr***'?

'He's come back and said "I don't like you," and fair enough, you don't like me, but all I've done is been honest and given constructive criticism on what you've done since losing to [Andy] Ruiz and Usyk, and where you're going now you're fighting Dubois.

'There's no need to get personal, no need to start on a man's hooter - looking pretty good by the way. 

'And then you've got your £10 and £20 notes rolled out on your bed saying ["get on my level, get on my level"] levels, it's all about levels'. 

Froch had also shared a video that Joshua had allegedly sent counting £10, £20, and £50 notes saying 'get on my level'. 

He continued: 'Where's the humble guy gone? Where's "remain humble, stay humble" [quoting Joshua]. 

'He's talking about levels and says I'm not on his level. But he's talking about money. Fair play to him - he's made a fortune, he's smashed it. 

'But let's talk about levels in terms of legacy and fights and career wins. A little fat kid from Mexico made him quit for f***'s sake. He spat his gumshield out and was looking around, looking for the corner, looking for the people in the crowd to help him out. 

'He got punched from pillar to post. The referee is looking at him - "do you want to carry on, do you want to keep fighting?" And what's he done? He's quit on his feet. 

'That is embarrassing - something the Cobra would never, ever do. And he can take that to the bank!' 

Froch has since claimed that Joshua has continued to send another 'barrage of abuse' on WhatsApp.

'I've shared 10 per cent of the messages. I mean, it’s schoolboy stuff,' Froch told BestOnlinePokerSites. 

'It's like plastic gangsters. It’s pathetic really, it's childish and it's a bit ridiculous. I've kept 90 percent of what he's said away. He's messaged me again, overnight, and deleted four of the messages.

'I've had a barrage of abuse, direct to me but I don't mind meeting up and dealing with it like men'.

Clearly, Joshua is happy to burn bridges with Froch and it seems that's also the case with one of his greatest rivals: Deontay Wilder.

Last month, Zhilei Zhang knocked out Wilder in the fifth round of their contest to put serious questions over the Bronze Bomber's future in the sport. 

If all had gone well, there had been talk of a fight between Joshua and Wilder in September of this year - an idea that has now been cast aside.

Asked at the time whether he was sad to see Wilder being knocked out, Joshua simply responded: 'No.'

Joshua appears to have tunnel vision as he heads into his September bout with Dubois and is clearly vying to be more independent after moving out of his mother's north London flat for a new mansion. 

Recently, he admitted that despite his wealth, he has only recently moved out from his mother's flat.

He said: 'I didn't want to leave my mum alone. I wanted to make sure that her foundations were strong – the nest was strong – so that when I leave, mum's good. For me, that's freedom. Knowing no matter where I am in the world, mum's happy and taken care of.'