Justin Bieber fan Mariah Yeater pictured with baby she claims is his

Mariah Yeater, the Justin Bieber fan who claims the singer fathered her three-month-old son backstage at a concert, has been pictured with the child.

 The 20-year-old is featured on the cover of U.S celebrity magazine Star with her son, Tristyn Anthony Markhouse Yeater, who was born on July 6.

And she has named the 17-year-old singer in a paternity lawsuit which she filed on October 31, saying also that she wants Bieber to provide 'adequate support for my baby'.

According to a statement Yeater made to a California court, her rendezvous with Bieber took place after she met him backstage after his concert at LA's Staples Centre last October.

The US website Radar Online reports that Yeater told the judge she later realised she was pregnant with what she believed to be Bieber's baby - but received no response when she contacted his representatives.

'On July 6 2011 I gave birth to a baby boy,' she added. 'That was exactly 36 weeks and two days after the sexual encounter with Justin Bieber.

'Based upon the timing as well as the fact there were no other possible men I had sex with that could be the father of this baby, I believe that Justin Bieber is in fact the father of my baby.'

Bieber's representatives have vigorously denied these claims and threatened legal action.

'While we haven't yet seen the lawsuit, it's sad that someone would fabricate malicious, defamatory, and demonstrably false claims,' they told E! Online.

'We will vigorously pursue all available legal remedies to defend and protect Justin against these allegations.'

Bieber himself also denied the claims on Twitter, writing: 'so Im going to ignore the rumors...and focus on what is real. an opportunity to help by doing what i love. Judge me on the music! Love yall! (sic)'

Although the claimant would have been aged 19 at the time of the alleged intercourse, Justin would have only been 16 - meaning that under Californian law she would be guilty of statutory rape of a minor.

A court hearing has reportedly been set for December 15.