FLOYD MAYWEATHER has goaded Manny Pacquiao ahead of Sunday's epic showdown in Las Vegas by claiming he is being underpaid by his promotional company Top Rank.

The richest fight in history is expected to gross between £266million to £332m, with Mayweather in line to earn £100m and Pacquiao in the region of £66million.

However, Mayweather insists it would have been a more lucrative night's work for the Filipino southpaw had his welterweight rival worked more closely with Mayweather Promotions.

"I know what goes on behind the scenes in the sport of boxing and you'll see the difference in our pay days this weekend," Mayweather said.

"If he'd have worked directly with us, he would have made a lot more money. I kind of know his number.

"Financially, he hasn't been treated right for this fight. And this fight is all about the money."

Mayweather also mocked the standard of Pacquiao's hotel when he stayed in Miami in January.

The two finest boxers of their generation met by chance at a Miami Heat basketball game and swapped numbers in a pivotal moment to agreeing the fight. Mayweather visited Pacquiao for talks in his suite later that night.

"Why did they have him staying in that type of hotel? It wasn't right," Mayweather said.

Pacquiao opted against attending Tuesday's glitzy grand arrival ceremony at the MGM Grand, instead choosing to stage a fans' rally at the Mandalay Bay. The decision disappointed Mayweather.

"I'm a professional. People have asked me why Manny isn't here. I don't know, but many people have spent a lot of money for this event to happen. It's all about being a professional," Mayweather said.