The Committee of Advertising Practice (CAP) said it could be misleading for marketers to make 'as seen' claims unless they had evidence of the products being editorially assessed, endorsed or reviewed on programmes or in publications.
CAP, which is responsible for writing the rules governing print and other non-broadcast advertising, said a ruling by the UK's advertising watchdog last month on ads for bed mattresses had "raised the bar" in how 'as seen' claims could be used.
"The ASA (Advertising Standards Authority) considered that using the product as an unbranded and unidentified prop in a homes make-over programme did not justify a claim that it had been ‘seen on TV’," CAP said in a statement. "Nor did it consider that the broadcast advertising of the product justified the claim."
"And in all but one publication, the ASA considered the advertiser had not justified the claims that the product had been seen in the Telegraph, Observer, Mail on Sunday, the Daily Mail or the Sunday Times," it said.
"Why did the ASA reach this conclusion? It considered that because consumers were likely to infer from the claim that those publications or programmes had exercised some form of editorial evaluation, endorsement or independent review – when this was not the case – the claim could mislead. So marketers wishing to make such claims about the coverage of their products should change them to 'As advertised in...' or similar," CAP said.
Under the CAP Code, marketing communications that "materially mislead" consumers or are "likely to do so" are prohibited.
Marketers are required to have "documentary evidence" in order to prove claims they make in ads. That evidence must be "likely" to be considered as "objective" by consumers and be "capable of objective substantiation". The CAP Code states that the ASA "may regard claims as misleading in the absence of adequate substantiation".
Making misleading claims in broadcast adverts is also prohibited under the BCAP Code. That Code sets out a separate set of rules governing acceptable advertising on TV and radio.