Rapper 50 Cent has thrown down the gauntlet to boxer Floyd Mayweather - by challenging him to read a page of a Harry Potter novel for an Ice Bucket Challenge.

The pair, who used to be business partners, have clashed since falling out, and 50 Cent has now taunted the boxer by saying he will donate $750,000 to a charity of Mayweather's choosing, if he can read a page without messing it up.

The rapper was making an Instagram video for the viral ALS Ice Bucket Challenge which he said he would forego in favour of asking Mayweather to read the page and post proof.

In a second video, posted hours later, 50 Cent, born Curtis Jackson, said: "We don't want to put pressure on you.

"We know you can't pronounce those words in the Harry Potter book so we gonna let you read Cat in the Hat."