As per the BBC, the ASA said the investigation follows three complaints made in April over the "labelling" of product advertisement posts, including Febreze and Flash.
Mrs Hinch said that "being authentic and transparent is incredibly important" to her and thinks her "community are clear about any content that is part of a commercial partnership, and that which isn't".
"I'm fortunate that brands want to work with me, but I only collaborate with those that I genuinely like and would recommend to people," the influencer added in response to the investigation.
She continued: "I continue to learn a lot, but feel my community are clear about any content that is part of a commercial partnership, and that which isn't. In fact, I'm overly cautious when it comes to these guidelines and will continue to be."
Under the Consumer Rights Act, all influencers and brands must disclose whether a post is sponsored or paid for - it is illegal not to.
ASA rules state all influencers must make their commercial relationships "transparent and unambiguous" at all times. They can do this by marking a post as an "ad".
A spokesman for the ASA said: "I can confirm that we are investigating Mrs Hinch as a result of receiving complaints in April this year around the issue of ad disclosure. We will publish our decision in due course."
Mrs Hinch has told her followers that she is a "brand ambassador" for Proctor & Gamble, and she regularly uses cleaning products from its companies on her Instagram stories.
Pretty52 has reached out to reps for Mrs Hinch for further comment.