Who is out in this case ?

[Mrhappybigpants]

No IFR in this instance, but lets say that there is a runner on first, the batter then pops the ball up between first and second base.The pitcher or first base or second baseman baseman, drops ( intentionally or not)the ball. Now the runner that is on first doesnt leave the bag as they figure the ball is caught. Opposing player picks up the dropped ball, tags the person at first as well as steps on first base to force the batter out. In this case who would be out, the runner at first, the batter or what.?????????