Ex-April member Hyunjoo is apologizing after being accused of 'backdoor advertising' on her personal Instagram account.

On August 27 KST, Korean YouTube channel 'Girl Group News' released a video titled "Are the 'backdoor advertising' suspicions about former April member Lee Hyunjoo true??," which eventually was spread to several online forums.

'Backdoor advertising' refers to a type of false advertising where influencers pretend to have purchased a product themselves when they were actually paid by a company to promote it. One instance raising suspicion from netizens is from August 24, when Hyunjoo changed the hashtags on a previously uploaded Instagram post from '#sponsor' to '#ad.' On August 23, she also went into posts that had not been tagged at all, editing in '#ad,' likely leading to the 'backdoor advertising' suspicions.

Since January of this year, many celebrities and influencers have been using hashtags to label advertisements or sponsored products provided to them by brands, preventing confusion among followers. Such labels were not mandatory until last year, with Korea's Fair Trade Commission announcing that violating advertisers should pay fines of up to 2% of sales or income or up to 500 million won.

In response to the accusations, Hyunjoo took to her Instagram account on August 29 to post a formal letter of apology, writing:

"Hello, this is Lee Hyunjoo.

I apologize for the confusion I've caused relating to the photos I've uploaded on Instagram.

I plan to upload the items that I have added an advertisement tag separately in YouTube ads, so in order to avoid misunderstanding, I labeled them as advertisements in advance.

Outside of that, the other sponsorship-tagged items are simply products I received as gifts, but I added those items to my photos to show my gratitude.

I am inexperienced in tagging, and I'm sorry for causing discomfort. Moving forward, I will do so with more consideration."

Meanwhile, Hyunjoo's full apology post can be seen below.