Closer mag claims to have snaps of Kate taken by paparazzi while she and William were 'on holiday' in France last week.
A teaser was posted on the magazine's website last night reading "World Exclusive; Kate and William in Provence: Oh My God!"
The site also published a pixelated version on the cover, which appears to show the Duchess in a bikini, apparently about to remove her top.
The magazine's editor said Harry would feel "less alone" when the issue hit the stands this morning.
She said the images show Kate "fully topless" and some show her nipples clearly.