Model/actress Jenny McCarthy is under fire after posting a joke about transgender people online while poking fun at a scandal surrounding Jennifer Lopez's boyfriend Casper Smart.

The On the Floor hitmaker's dancer beau has been at the centre of controversy after reportedly cheating on his superstar girlfriend with a transgender bikini model.

On Tuesday (03Jun14), MCCarthy decided to weigh in on the rumours, and took to to write, "Did Jennifer Lopez's boyfriend cheat on her with a transsexual model? I heard JLo gave him an ultimatum: 'it's either me or her/him'"

The Tv personality soon deleted the tweet after receiving a barrage of responses criticising her for the joke.

Author Kelly Oxford wrote, "Hey @JennyMCCarthy your last tweet was really transphobic. I'm a 'learn and be better' type, so I thought I'd let you know. Peace."

MCCarthy has yet to comment on the furore.