Behind the brick walls topped with curls of barbed wire, the atmosphere in Birmingham prison is calm. The Church of England chaplain munches his lunchtime sandwiches next to the chip-eating imam, who describes the place as "the prison United Nations" for its variety of coloured faces.

The diversity officer sifts through complaints - each of which he will investigate - and a large Sikh prison officer, Raj Mander, explains how a transformation of the jail over four years has helped create a national benchmark for race relations in prisons.