Define who the diverse people are

Keith Vaz MP has just announced that the Home Affairs Select Committee will "explore with (former Chief Constable) Mike Fuller and (Chief Superintendent) Dal Babu Diversity in the police".  Perhaps Keith Vaz could also define who the diverse people are?  How exactly does one define BME people? (if I self-define myself as BME is that good enough?).

Or is it a case of "I know BME people when I see them"?