Ministers have been rapped over a Facebook advert which showed a white prison officer talking to a black inmate.
The Advertising Standards Agency said it had “perpetuated a negative ethnic stereotype about black men as criminals”.
Officials at the Ministry of Justice were told to axe the ad - which was aimed at encouraging people to work in the prison service - and “ensure they avoided causing serious offence on the grounds of race”.
The department appealed against the against the ASA ruling after an independent reviewer said it contained “serious flaws”. However, the appeal was today rejected by the watchdog.
In their judgment, they said: “The ad showed a white male prison officer and black male prisoner interacting in a prison setting.
“The prisoner was only seen from behind, with his face not visible and his arms crossed, and wore his hair in an afro style, with an afro pick comb.
“We understood the hairstyle and hairstyling tool worn were important aspects of black culture, and were uniquely associated with it. We considered those elements had the cumulative effect of emphasising the prisoner’s race, rather than his inclusion in the ad as an individual prisoner.
“As a result, in the context of a prison scene, we considered the ad had the effect of perpetuating a negative ethnic stereotype about black men as criminals. On that basis, we concluded that the ad was likely to cause serious offence.”
The ruling added: “The ad must not appear again in the form complained of. We told the Ministry of Justice to ensure they avoided causing serious offence on the grounds of race.”
A Ministry of Justice spokesperson said: “We appealed the decision in order to reassert the important principle that we should be able to represent real officers and prisoners in our advertising.
“This photo was one of many we use to help potential prison officers understand what to expect from the role, and to show the priority we place on building constructive relationships with prisoners.”