Indeed, "propping" products for shoots was considered no more unethical than lighting a scene for the best effect or retouching a picture.

Nowhere was trickery more commonplace than in food advertising. One example was the use of mashed potatoes coated with resin as a substitute for ice-cream as the real thing melted too quickly.

So nobody batted an eyelid when Robson Ballantine, an art director at BBDO in New York, resorted to some visual sleight of hand in 1968 when photographing a campaign for Campbell’s new Chicken & Stars soup.

Ballantine’s problem was that the solid ingredients sank to the bottom of the broth. He solved it by putting marbles in the bowl to push the chicken and pasta to the surface.

He had no idea of the storm he was about to unleash, resulting in the intervention of the US Federal Trade Commission and a string of legal actions that went on for two years.

The furore also gave birth to a concept that can be ordered by the FTC in serious cases of deception – corrective advertising.

The FTC began an investigation into BBDO’s campaign in April 1968. Both client and agency agreed not to use such techniques again and the case seemed closed.

However, the following year, the FTC made the details public, issued a formal complaint against Campbell’s and invited public comment.

The result was petitions and appeals involving 14 federal judges. In December 1972, the FTC dismissed the case against Campbell’s, which was never ordered to run corrective advertising. But the concept had been born.

Things you need to know