A painting by Banksy of a judge using a gavel to beat a helpless protester appeared on the walls of the Royal Courts of Justice before quickly being covered up by guards.

Banksy confirmed the artwork was his by posting a picture of it on Instagram on Monday morning. Local workers said security guards were in position in front of the artwork, which is thought to be a reference to pro-Palestine protests.

One, Matteo, said he passed by at 8.30am on Monday when the guards were trying to stop people from taking pictures. More staff then arrived with supplies to cover it up.