A 'flinch' from Hannah's son in a viral video has now led to an investigation.

A TikTok mum influencer known for documenting her family's life online is being investigated due to "numerous reports through Child Protective Services and police" over a video of her toddler.

Utah influencer and nurse Hannah Hiatt, who goes by @hannah_bhiatt on the platform and previously went by @nursehannahbh, is being investigated by Ogden Police, a spokesperson told People on Monday.

They said the investigation was sparked by several reports of concern made to Child Protective Services and police following a video in which Hiatt's young son James appears to briefly flinch and hide his face as his dad walks towards him.

"There is a detective assigned to the case," a department spokesperson said. No further details on the investigation were provided.

In the since-deleted video, James was sitting in the child seat of a grocery cart during a family outing when he throws his hands up over his face.

The clip sparked concern among several viewers, who claimed James was scared of his parents, and even prompted several parents to make videos showing whether their own children would flinch in that situation.

One commenter went as far as comparing Hiatt to controversial family YouTuber Ruby Franke, who was convicted of child abuse.

Watch: Mum counts 17 dirty diapers around house.

Hiatt, who is known as the "17 diapers mum" for a viral video counting dirty diapers strewn across her house, recently addressed the controversy.

She slammed the comparison with Franke as "comical", saying people were clutching at straws for views online.

"We live in a world nowadays where people will turn nothing into something," she said in a video on December 1.

She said her children were "happy, healthy and well-nourished".

"They're running around playing. That should be a pretty good indicator that everything's fine, it's great," she said.

"They always have a clean bum and never have a dirty diaper on."

Content creator Hannah Hiatt. Image: YouTube/@hannah_bhiatt.

Setting the record straight, Hiatt shut down allegations against her husband, saying he and their toddler have the "strongest father-son bond".

"My husband is the sweetest, nicest, kindest, most-loving, most-nurturing father in the entire world," she said in a separate video on November 30.

Hitting back at critics, Hiatt said her husband and James had a playing style where they scare each other.

"In the video that you guys are all freaking out about, they're just playing," she said.

"Nothing's going on. From the moment that my husband wakes up in the morning, to the second he goes to bed, he is only thinking about our children and our family and what's best for us."

Mamamia has contacted Ogden Police for comment.

Feature image: YouTube/hannah_bhiatt