JK Rowling’s rumoured political fairy tale has been written and is currently hanging in the author’s closet.

In an interview with CNN published on Monday, the Harry Potter author revealed she has finished her long-awaited story, but is not sure if it will ever be published.

The story is not currently down on paper, but on a party dress Rowling wore to celebrate her 50th birthday.

“The theme of my 50th birthday, which I held at Halloween – even though that’s not really my birthday – was come as your own private nightmare,” she explained.

“And I went as a lost manuscript. And I wrote over a dress most of that book.

“So that book, I don’t know whether it will ever be published, but it’s actually hanging in a wardrobe currently.”

Rowling’s decision to put Harry in a cupboard derived from her fear of closed spaces

Rowling spoke of the story while discussing her children’s charity Lumos, which focuses on helping institutionalised children.

The Potter writer said she realised how important it was for a charity like this to exist after she seeing a distressing image of a child in a newspaper.

“I turned back and I read the story. And the story was about an institution in the Czech Republic where this boy, among many other children with special needs, was being kept, I would say, at least 20 hours out of 24 in a cage-bed, which is exactly as it sounds,” she said.

“I was just appalled and horrified.”

This also led her to speak about her worst fear, and how it made her rethink the way she portrayed Harry Potter’s character.

“So although I didn’t think that’s like Harry in his cupboard, I suppose why did I put Harry in the cupboard?,” she questioned.

“Because this is my fear, being trapped and being powerless, just powerless to get out of that space.”