Celebrated author J.K. Rowling has written a biography of the lesser-known `Harry Potter` character, Celestina Warbeck, on a fan site.

The Scottish author published the profile of the singer, who is referenced in the popular wizarding book series, though never appearing directly, on fan site - Pottermore - after describing her as one of her favourite unseen characters and likening her to Welsh superstar Dame Shirley Bassey, reports contactmusic.com.

`Celestina Warbeck is one of my favourite 'off-stage' characters in the 'Harry Potter' series, and has been part of the Potter world ever since its inception,` she was quoted as saying.

`Although we never lay eyes on Celestina during the whole seven volumes of the Potter books, I always imagined her to resemble Shirley Bassey in both looks and style.

`I stole her first name from a friend with whom I worked, years ago, at Amnesty International's Headquarters in London; 'Celestina' was simply begging to be scooped up and attached to a glamorous witch.`

The biography, available to read on the subscription-only site, details the establishment of a choir at wizarding school Hogwarts to cater for Celestina's talents.