The woman in question reportedly filed a paternity suit against Justin, claiming she and JB had a special hug backstage at a recent concert at the Staples Center in L.A. … and 9 months later, she popped out a baby, baby, baby, oh. 

But we’re told Justin believes the story was “completely made up.”

Bieber just tweeted about the situation — saying, “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!”