As if a reported prize pool of around $A380 million were not enough, Floyd Mayweather Jr and Conor McGregor will be fighting for a ridiculously lavish ‘Money Belt’ this Sunday.

The boxing champion and the UFC star will do battle in Las Vegas this weekend in front of a sell-out crowd of around 20,000 and a pay-per-view TV audience in the millions.

The fight – long discussed given Mayweather Jr’s dominance of boxing and McGregor’s regular UFC wins and fanatical following – always seemed unlikely, given the American had retired.

But he was lured out of retirement in May, with the promise of a massive payday and a chance to take his career record to 50-0 simply too good to refuse.

McGregor is given little chance in the fight, given he has never boxed before. Because of that fact, it is not an officially sanctioned bout.

That means no championship belt is up for grabs – unlike other big title fights, such as Jeff Horn’s ‘Battle of Brisbane’ with Manny Pacquiao, in which the former Aussie school teacher won the WBO world welterweight title.

So, without an officially recognised belt, fight organisers have opted for possibly the most opulent creation imaginable.

The belt is mounted, naturally, on crocodile leather and is studded with 3360 diamonds.

Add in 1.5kg of 24-carat gold, 600 sapphires and 300 emeralds, and you have what one of these two men will win in what is commonly referred to in the United States as ‘Sin City’.

If it sounds expensive, that’s because it is.

The belt, created by the World Boxing Council, is estimated to be worth around $A6.3 million.

It was unveiled by WBC president Mauricio Sulaiman at a glitzy press conference on Wednesday that doubled as the latest chance for Mayweather Jr and McGregor to trade barbs.

Mayweather Jr, who posed for photos with the belt, won a similarly designed – but not as expensive – belt for defeating Manny Pacquiao in a 2015 bout that still rates as the richest fight in the world.

That bout brought in estimated revenue of $A630 million, but it remains a chance that the Mayweather Jr-McGregor fight will exceed that.

McGregor arrived nearly two hours late for the most recent press conference, while Mayweather Jr bemoaned his opponent’s lack of professionalism.

He added: “It’s not gonna be easy, Conor. It’s not gonna be easy. Remember: [Manny] Pacquiao got bombs, Canelo [Alvarez] got bombs, Shane Mosley had bombs. And all those guys are going in the hall of fame.

“One thing about me, I’ve got a granite chin. But remember this: The same way you give it, you have to be able to take it.

“When it’s all said and done, one thing I know that I can do: I can fight. I can give it and I can take it.

“But for me to be 49-0, it’s obvious: I’m not receiving it. I’m giving it.”