The billboards were run by Belfast-based Nicofresh
A series of adverts in Belfast have been banned after being branded as racist.
The billboard poster for Nicofresh electronic cigarettes featured an elderly white woman sitting on a couch alongside a young black man.
The man had his arms around the woman as the woman held an electronic cigarette.
Text alongside the image stated "NO TOBACCO. NO TABOO".
The British Advertising Standards Authority (ASA) said six complainants challenged whether the ad was offensive on the grounds of race, because "it implied that an interracial relationship was socially unacceptable".
Four of the complainants challenged whether it was offensive on the grounds of age.
Belfast-based Nicofresh had said the campaign was based on the observation that, over the last 30 years, cigarette smoking had come to acquire taboo status in Irish and British society.
"Smoking was banned in most public places, meaning that smokers were not free to smoke in most of the everyday smoking situations that make up the 'public sphere', including public transport, public houses and cinemas", it said.
It added that the ad asserted that, thanks to Nicofresh, and the social permissibility of e-cigarettes, smokers could indulge in a variation of social smoking without feeling the sense of disapproval that smoking could result in.
The ASA considered that consumers were likely to interpret the ad to mean that, contrary to the relationship depicted, to smoke e-cigarettes was not a taboo issue.
"We noted the pronounced age gap between the man and woman, the fact they were a couple, and that the image was accompanied with the text 'NO TOBACCO. NO TABOO'.
"We considered that consumers would believe that the ad was presenting a relationship between an older and younger individual, particularly an older woman and a younger man, and a couple of different races, as something that was unusual or socially unacceptable.
"Because of that, we concluded that the ad was likely to cause serious or widespread offence on the grounds of race and age."
The ASA said the ad must not appear again in its current form.
Nicofresh also has offices in Dublin.