Kylie Jenner 'freaking out' over Forbes' accusations she's not a billionaire

Kylie Jenner reacted to the Forbes article on Twitter. Photo / Getty Images

Kylie Jenner is reportedly "freaking out" over claims she is not, in fact, a billionaire.

Forbes magazine, which declared the star the youngest self-made billionaire of all time last year, now says a closer look at the makeup mogul's finances shows evidence Jenner has been "inflating the size and success of her business".

The report claims: "Kylie's business is significantly smaller, and less profitable, than the family has spent years leading the cosmetics industry and media outlets, including Forbes, to believe."

Jenner took to Twitter, tweeting: "i thought this was a reputable site. All I see are a number of inaccurate statements and unproven assumptions lol. I've never asked for any title or tried to lie my way there EVER. period. [sic]."

And Jenner's lawyer, Michael Kump, demanded a retraction in a statement on Friday.

Behind the scenes, a source has told the Sun: "Kris and Kylie are freaking out and fear that this is going to hurt their brand, and even worse, they could be in trouble with the government."

It has been alleged Jenner, 22, has over-estimated the value of what is an extremely successful company, Kylie Cosmetics. Forbes now estimates Jenner to be worth $US900 million.

Last year Forbes reported Jenner as " ... the youngest-ever self-made billionaire, reaching a ten-figure fortune at a younger age than even Mark Zuckerberg."

The mother-of-one has also capitalised on her huge social media following.

The publication reported in January that Jenner sold her cosmetics brand to Coty for US$1.2 billion (NZ$1.9b), but Forbes states that the size of her business empire isn't actually as big as it seems.