A BOARDING school has apologised after its pupils sparked outrage by 'blacking up' for leaving pictures. 

Photos posted online showed the students at an £33k-a-year Oratory School, near Woodcote in Oxfordshire dressed as slaves. 

The pupils had been banned from taking part in the Catholic School's traditional fancy dress 'informal photo' but snuck back later to take their own. 

Three were wearing black make up and holding sheets of cotton while two others dressed in suits and posed with guns.

A spokesman for the Oratory School said: "The Headmaster was present for the photo and refused to let the offensively dressed pupils participate.

"The photo - the existence of which we were unaware - was taken and posted on social media was taken unofficially and in no way with the consent of the school.

"We are extremely shocked and saddened that this has happened and apologise unreservedly for the offence caused. We are dealing with this internally."