Banksy has confirmed an artwork which has appeared on a London police box is his own, bringing this week’s creations by the anonymous artist to seven.

The latest artwork, featuring a school of swimming fish, appeared overnight on a police box in the City of London.

Because the style differs from Banksy’s usual silhouette pictures, his latest creation raised doubts it was indeed his.

But Banksy has now claimed the artwork, which makes the police box look like a giant fish tank, as…