Justin Bieber baby scandal - Mariah Yeater ex believes he's the dad?

Mariah Yeater's ex-boyfriend Robbie Powell reportedly believes that he, not Justin Bieber, is the father of baby Tristyn.

Yeater has accused Bieber of fathering her infant son in an October 2010 sexual encounter following an LA concert.

Sources close to Powell have told TMZ that he is angered by Yeater's claims and is willing to take a DNA test to prove he fathered her baby son.

The insider added that Yeater has privately admitted to Powell that she made up the accusations against Bieber.

Powell is apparently considering a television interview to discuss his side of the story.

Lawyers for Yeater haven't commented on the report.

The website previously published text messages allegedly sent by Yeater where she appeared to name Powell as Tristyn's dad.

Last week, Bieber took a DNA test at a New Jersey medical facility in order to prove that Yeater's allegations are false.

The 'Mistletoe' singer has previously denied that he ever met Yeater.

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Watch Justin Bieber discuss the paternity test on The Late Show with David Letterman below: