Katy Perry dresses like Freddie Mercury to raise money for his charity

'I Kissed A Girl' hitmaker Katy Perry has dressed up like her idol Freddie Mercury in order to raise money for the late star's charity.

Katy, 26, is seen wearing a moustache, cropped wig and bright yellow jacket to promote the Freddie For A Day campaign, which is raising money for the Aids charity the Mercury Phoenix Trust, Contactmusic reported.

To mark what would have been Mercury's 65th birthday, fans are expected to don replicas of his flamboyant stage outfits alongside his bandmates Brian May and Roger Taylor at a London hotel on September 5.

Katy, who has long cited the rocker as the biggest influence on her musical career, will be joining the party.

Mercury died from AIDS-related pneumonia in 1991 at the age of 45.