Lawyers representing Jennifer Lopez's ex-boyfriend have threatened to take legal action over a false story about his sex life.

Dancer Casper Smart, who is believed to have split from Lopez several months ago, has issued a warning to editors at TheDirty.com through his attorneys, urging the publication to retract a story which suggested he had relations with two transsexuals he met through Instagram.com.

Lawyers representing Smart, who denies all claims he cheated on the superstar, have sent a letter to the site's bosses threatening to take legal action if they do not publish a retraction. They have also reportedly sent letters to the two transsexuals.

The website's founder Nik Richie has hit back at Smart and his team, telling Tmz.com, "Casper, go get a real job. I heard Instagram is hiring over in their compliance department... Stop blaming everyone else for your problems."