Rapper Mellow Rackz has been accused of punching her boyfriend ... The 22-year-old, who boasts more than 1 million followers on Instagram, allegedly unleashed after running into the woman ...

Rapper Mellow Rackz is in police crosshairs after cops say she got into a fight with her boyfriend's ex-girlfriend and swiped the woman's cell phone.

Rapper Mellow Rackz is being investigated as a suspect ... Rackz, who has over one million Instagram followers, hasn’t commented on the situation. TMZ says their sources have told them ...