107 complaints were made about bloggers to the advertising watchdog in 2018.

It compares to 11 complaints about 'marketing communications involving advertisers (or brands) and bloggers' in 2016, and 105 in 2017.

However, the Advertising Standards Authority for Ireland (ASAI) said there is sometimes no basis for investigation under its guidelines if the material involved isn't advertising.

According to the ASAI code, bloggers should at a minimum include the hashtags '#Ad' or '#Sp' when posting marketing material.

The guidelines note: "Where celebrities are sponsored by brands or paid directly to promote a brand’s products, it must be clear that their posts are marketing communications."

In one case, blogger Rosie Connolly was found in breach of the new code for promoting a Rimmel foundation with images using phone camera filters.

The posts were removed so the ASAI said no further action was required, although the watchdog reminded everyone involved to ensure that any pre- and post-production techniques 'do not mislead about the attributes of the product being advertised'.

There has been increased scrutiny in recent years over how 'influencers' and celebrities highlight marketing or paid content on social media.

Last year, the ASAI warned bloggers and social media influencers that they'll be named and shamed if they mislead their followers.

Last month, meanwhile, more than a dozen celebrities in the UK agreed to make it clearer when they are being paid or rewarded to post on social media.