E! Presenter Giuliana Rancic stunned viewers after she presented the evening news naked as part of a bet.

The 38-year-old anchor joined her co-star Jason Kennedy for the broadcast in just her birthday suit after being dared by her Fashion Police co-host Joan Rivers.

The mother-of-one is said to have agreed to the risqué move to help kick off Rivers' outrageous 80th birthday celebrations.

Rancic spent the whole segment standing naked in front of a screen while a black 'censored' box protected her modesty from millions of viewers.

Kennedy, however, opted for the more traditional attire of dapper navy suit and pink shirt and tie for the on air show.

One viewer tweeted: "Wondering if @GiulianaRancic was really naked. Still can't believe that just happened. Lol"

The E! network has been celebrating the veteran comedian's milestone birthday with a "Joan It All" take-over which has seen a double dose of the star's Fashion Police every night, as well as some hijinks involving chloroforming The Soup and Community star Joel McHale.