UK-based YouTubers have been warned by the Advertising Standard Authority (ASA) that they must mark videos that are promoting a product.

Bizarrely the warning comes after complaints regarding videos about Oreo biscuits, which BBC journalists argued were clearly identifiable as pieces of marketing.

"We noted that the presentation of each ad was very much in keeping with the editorial content of the respective channels and that the fact that the videos were marketing communications would therefore not be immediately clear from the style alone," said the ASA in a statement.

In response the company behind Oreos in the UK, Modelez UK Ltd, said they would be changing the videos.

ASA spokesman Lynsay Taffe told the BBC they would be looking at online videos more closely in the future, saying: "Brands and vloggers now have to make it very clear, before you click on a video, that it's a promotional video."

MP Ben Bradshaw also chimed in, echoing the sentiment. "There are strict rules that govern television and other advertising and it seems to me that there's a bit of a loophole when it comes to online, videos and YouTube," he said.

Over the years YouTubers have courted controversy due to deals they have struck with publishers and distributors to make videos about their product. In the realm of video games this was most recently explored by The Escapist's Jim Sterling who tackled shady goings on relating to Middle-Earth: Shadow of Mordor.

The issue isn't far removed from that of advertorial in journalism - the act of adverts masquerading as editorial content.