The so-called National Internet Survey (Nationale Internetumfrage) has been recruiting participants by telling them they have been “selected” and offering them “gifts” including iPhones in exchange for completing a three-question survey.

But participants who answer the questions are then asked for their mobile number, with the small print explaining that they are in fact subscribing to a mobile game service costing €4.99 per week. Later, “gifts” are referred to as “prizes” – which, according to the small print, National Internet Survey is not responsible for supplying.

The website says it is run by an “independent research organisation”, but Raimund Wildner of the IMSF – the body set up to protect and promote the image of research among the German public – said today: “A legitimate survey is never combined with advertising or sales.” The IMSF also said that respondents in reputable surveys should not expect rewards whose value bears no relation to the time spent taking part.

The National Internet Survey website points users to Düsseldorf-based company Net Mobile for information about subscriptions. In turn, Net Mobile appears to be linked to 2WayTraffic Mobile, a Netherlands-based subsidiary of Sony Pictures Television – although it is not clear what the nature of the relationship between the two companies is.

Research left messages with Net Mobile and Sony Pictures Entertainment (parent company of Sony Pictures Television) today but had received no response by the time of publication.