UK watchdog the Advertising Standards Authority (ASA) is the latest regulatory body to warn influencers that their commercial relationships must be fully declared in paid-for posts and videos.
"Too often we are seeing content that is clearly an ad and not identified as one. We are trumpeting this a bit and trying to raise awareness," ASA chief executive Guy Parker told the Guardian.
"We are trying to deal with cases that come across our desk to provide support, advice and clarity to brands and social influencers so they know when and how to disclose content."
Complaints to ASA about social-media advertising have nearly tripled since 2012, reaching 1,824 complaints in 2016. However, the body said that only a small percentage of these complaints relate to social-media influencers, as opposed to other kinds of social ads.
According to Parker, more influencers are using the #ad hashtag to indicate a paid-for post, but that "although we are in a better situation than a few years ago, we are still not where we need to be and that is very often due to ignorance".
The UK's Committees of Advertising Practice (CAP) recently published a blog post on the ASA website making its position clear on how influencer marketing should be declared.
"When the brand has control over the content of the post and rewards the influencer with a payment, free gift, or other perk, the post becomes an ad," it explained.
"If the commercial intent isn't clear from the overall context of the communication, it should be labelled as an ad so as not to break the ASA’s rules and mislead the influencer's audience. Consumers should always be aware when they are being advertised to. Failure to disclose the commercial relationship an influencer may leave a brand at risk of a complaint to the ASA."