Katy Perry's fans were sent into a frenzy on Wednesday when a saucy photo apparently showing the pop star posing seductively in a bikini went viral - until it emerged the image actually featured a topless model lookalike.

Followers of the I Kissed a Girl hit-maker thought they had struck gold when a photo of a pouting, sultry brunette posing in a striped red-and-white bikini while touching herself intimately began circulating on Twitter.com.

The image was re-tweeted so many times by excited male fans of the singer that it was listed in the 'Top Photos' under a search for Perry - but followers were left disappointed when the woman's true identity was revealed.

The sexy brunette in the snap was in fact Rosie Jones, a 22-year-old glamour model who regularly poses topless in British tabloid The Sun.

Jones herself saw the funny side of the misunderstanding, later writing on the website, "Why does everyone keep tweeting this pic as katyperry!? I'm flattered, but I'm not sure she would be!"