Conor McGregor "whimpers like a girl" when he is hit by body shots, according to his former sparring partner Paulie Malignaggi.

The former two division world champion quit as McGregor's sparring partner on Friday after photos of their sessions were leaked on social media, with the Irishmen preparing for his much-publicised fight with Floyd Mayweather Jr.

Malignaggi, who retired earlier this year, became enraged when photos of a recent sparring session were leaked to social media - and all of the photos showed McGregor landing big punches, including one photo that gave the appearance that McGregor had scored a knockdown. Malignaggi claims McGregor shoved him down to the mat.

Hall of Fame referee Joe Cortez, who got hired to work McGregor's sparring sessions, said the recent punch-up between the MMA star and Malignaggi became extremely heated and required his intervention to separate the fighters.

McGregor praised Malignaggi was being a game fighter, but also said the Brooklyn boxer "got his ass kicked" during the sparring session.

And in a string of tweets, Malignaggi hit out at UFC star McGregor's ability in the ring ahead of the super-fight.

"This coming week I'll actually start to discuss a bit what happened [on] Tuesday, he whimpers like a girl when he gets ripped to the body," Malignaggi wrote.

"I won't speak tactics of his, that I wouldn't do, I still have some ethics I'm not Conor but def[initely] will give the story straight about stuff."

Malignaggi added he regretted sparring with McGregor and claimed that he was not paid for the experience.

McGregor is due to face unbeaten fighter Mayweather at the T-Mobile Arena in Las Vegas on August 26. The contest will be McGregor's first inside of a boxing ring. Mayweather (49-0, 26 KOs), 40 years old, has been away from the ring since announcing his retirement from the sport in September of 2015.