The leaflet, for Lifestyle Services Group, depicted a criminal line-up containing just four black men, one with a frightened look on his face.
The text read: "Sometimes you might wish someone had stolen your identity."
The Plymouth and District Racial Equality Council complained that because there were no white people in the line-up, the ad implied black men were criminals.
The ASA upheld the complaint and ruled that the mailing reinforced a stereotype that black men are criminals and was likely to cause serious or widespread offence.
Lifestyle Services Group said it had not meant to cause any offence and reassured the ASA that the remaining leaflets had been destroyed.
- Comment, page 60.