Floyd Mayweather Sr has launched a stinging attack on Adrien Broner

Floyd Mayweather Sr has launched a stinging attack on Adrien Broner in the wake of his points defeat to Shawn Porter on June 20.

The three-weight world champion failed to re-establish himself as one of the world's leading fighters and suffered a second career defeat in Las Vegas despite knocking Porter down in the final round.

Floyd Mayweather Jr had helped Broner in training in the lead-up to the fight and even officiated the weigh-in, but his father was less than impressed by the 25-year-old's efforts inside and outside of the ring.

Mayweather Sr told BoxingScene.com: "I'll be honest with you, I voted for Broner. I was thinking Broner was going to win. You can't keep making excuses for people. He knows right from wrong. If he did it wrong and got his ass whooped, that is what's supposed to happen.

"He's not no top-ranked fighter in the rankings. He held all night. Broner looked like nothing. All that grabbing and holding.

With all the stuff he does, the women, the drinking, he's not going to do nothing. He looked like a bum.

"With all the stuff he does, the women, the drinking, he's not going to do nothing. He looked like a bum.

"First, he needs to learn how to fight. If he wants to learn how to fight then he needs to come see me or else forget it, done. My whole saying is it's my way or the highway and no other way. 

"All the things Broner was saying, none of it was true. Don't get me wrong, I see where he's got ability, but with all the s*** with these girls and the drinking, he's never going to get nowhere."

Broner's trainer, Mike Stafford, was quick to fire back at Mayweather Sr for his appraisal.

Stafford told The Sweet Science: "What Floyd Sr is doing, he's an opportunist living off his son, saying he's the best off his son. He don't know nothing about developing talent, someone else's son. You've got to be loving, caring and go the extra mile.

"He has guys coming to his gym, coming off the bus to him. I might have to go pick a guy up. Go in to the hood. There are guns, drug dealers, crackheads. They have guns out, they see me and go: 'Oh it's cool, it's coach Mike.' Late at night, early in the morning."