Russell Brand ripped into an audience member who heckled his ex-wife Katy Perry over the weekend.

The British comic was doing a stand-up routine in Atlantic City, New Jersey when a guy "randomly yelled out" his former love's name.

The couple divorced early this year after 14 months of marriage but Russell still defended the pop star's honour.

"This guy randomly yelled out, Katy Perry,' and at first Russell didn't make much of it," an eyewitness told Life & Style. "But in a little while, he did it again and Russell lost it."

"He actually climbed down off the stage, made the crew turn the house lights up and told the audience to point the guy out.

"He tore into him for maybe three or four minutes, standing right there in the middle of the crowd with the lights up."

Russell told the man that he "was hoping that your personality was a result of physical beauty, and then I saw you."

"He went on to attack everything from how good he thought the guy would be in bed to accusing him of being impotent," the audience member added.