An investigation has been launched into whether TikTok is doing enough to keep children off its platform.

The probe by media regulator Ofcom comes a month after the UK government announced that under-16's would be banned entirely from a range of platforms.

Ofcom will examine how the video-sharing app assesses if a user is a child and whether it has adequate systems to prevent children from viewing harmful content.

"We're confident that we meet our Online Safety Act obligations and will work with Ofcom to demonstrate it," a TikTok spokesperson said.

It follows a review by regulator in May which criticised the platform for not being "safe enough" for children and called for stronger action on children's online safety.

Kate Davies, Ofcom's group director for strategy and research told BBC's Today programme: "This is where TikTok comes in. We found that some method of age checks being used by social media are not working well enough".

At the heart of the regulator's probe into the platform is its use of technology known as "age inference".

This essentially relies on estimating how old a user is based on how they use the platform, such as the videos they watch or others they interact with.

Davies said Ofcom had "serious doubts" over whether such tools are good enough at checking the age of users.

The regulator requires social media platforms, among others, to use "highly effective" methods to check users are old enough to use them and prevent children from seeing harmful material.

"We have very serious questions about whether age inference can be highly effective," she said.

But a TikTok spokesperson said: "We strictly enforce age-appropriate experiences through expert-informed platform rules and advanced age inference technologies, in line with major industry peers."

They said the company had invested "billions" in online safety since launching in the UK eight years ago.

Ofcom's review of TikTok's age checks are part of a broader clampdown on sites failing to prevent children encountering adult content, such as pornography, and other harmful material.

Under the Protection of Children's Codes, which took effect on 25 July last year, sites with such content must use methods such as face scans to check a UK visitor is over the age of 18.

But the regulator has since had to take action, including issuing large fines, against dozens of adult sites over suspected or proven non-compliance.

Its investigation into TikTok shows scrutiny is now being stepped up for social media sites.

TikTok is not alone in using so-called age inference tech, with Instagram also deploying it among other methods to identify where a person might be a child lying about their age.

The platform says UK users are placed into an age-appropriate experience for under-18s by default until they are understood to be an adult.

It says people who fail to enter a date of birth that puts them over the age of 13 when they create an account are prohibited from making a new one, for instance by trying to enter a different date of birth.