The 26-year-old 'Bad Romance' singer is seen hugging her knees to her chest in the snap, and appears to be protecting her modesty in a flesh-coloured thong.
GaGa recently responded to the current speculation surrounding Kristen Stewart's fling with British director Rupert Sanders, tweeting: "Geez this Kirstew Rob stuff is brutal. Makes me sad the way press acts. Hope they're OK."
On her Little Monsters website, GaGa also posted pictures of her recent reported sleepover with actress Lindsay Lohan and Lana Del Rey at the Chateau Marmont in Los Angeles.
The blurred picture shows Lady GaGa hugging Lohan and celebrity photographer Ellen von Unwerth in a room in the famous hotel.
TV presenter Melanie Sykes has recently posted a nude snap of herself on a chair on the microblogging site, as has singer Courtney Love.