A complaint was upheld against the 21-year-old by the ASA after she shared a photo promoting an outfit for online retailer Pretty Little Thing.
The organisation reported the post due to the fact it failed to be identifiable as an advert.
The retailer and Ms Hague argued that the post wasn’t part of her contractual role and fell outside of their partnership due to her own personal genuine interest.
However, the ASA said that Molly-Mae must include phrases such as “#ad” on posts to make her role as an ambassador for the brand absolutely clear.
The now deleted post was shared on September 26, 2019, and showed Molly-Mae modelling a Pretty Little Thing teddy-bear coat with the caption: “A/W, I’m ready [brown leaf emoji]”
Molly Mae also tagged Pretty Little Thing in the post to her account.
This comes after the former Love Island beauty uploaded an 18 minute video blog onto YouTube on Tuesday night that documented her recent getaway to the Maldives with boyfriend Tommy Fury – despite the star claiming she was embarking on a social media detox.
The footage began the evening before the couple jetted off, as they filmed themselves cuddling up in bed together in their Manchester apartment.
The YouTube star then shared with her fans: “We are using this holiday as a social media detox.”
However, despite her resolutions, the reality TV pair, both 21, then went on to film the entire trip alongside littering Instagram with a number of photos.
They showed themselves eating at the airport ahead of boarding their flight and added snippets of them in the air in the footage – that is part one of two.
Molly-Mae filled the video with clips of the couple’s lavish hotel rooms as well as zooming in on their lunch and drink choices.
They showed fans them enjoying walks together, Tommy suffering from heat rash and Molly discussed being bitten by bugs – as well as them counting down as they rang in the New Year.
Molly-Mae is yet to upload part two of her holiday vlog.
Ahead of the winter series of Love Island which is set to splash across our screen this Sunday, Molly’s sister Zoe seemingly made a cutting remark about the show in an Instagram caption.
The 23-year-old hinted the ITV show edited her sister in a bad light as Molly-Mae became a victim of severe trolling during her TV stint.
The blonde bombshell was cruelly nicknamed “Money-Mae” as fans accused her of only romancing Tommy Fury to attempt to bag the £50K prize fund.
This was something she proved wrong when they narrowly lost but live happier than ever in their Manchester pad.
Ahead of the first ever winter series, the older sister issued a warning to family and friends of the new islanders heading into the villa on January 12.
Zoe stood by Molly-Mae as she shared a lengthy statement in defence of her sister against cruel trolls.
She wrote: “You know the person better than anyone, people will have their opinions, say vile things, the show will edit to make them come across a certain way.”
Zoe also opened up about her experience of tackling her sibling’s trolls.
She wrote: “Advice to family/friends/people running accounts of the new islanders this year.”
“Nothing you do will make a difference to the things you will read.”
“All I can say is every time you go to search your loved ones names on twitter, join a love island ‘banter’ group on Facebook or search for articles about them, please think twice as it is possibly the worst thing you can do.”