Police are investigating the possibility of foul play in the case of Bobbi Kristina Brown, who was placed in a medically induced coma after being found unresponsive in a bathtub last weekend, celebrity news site TMZ reported Saturday. Georgia investigators reportedly have opened a criminal investigation.

TMZ, citing an unidentified law enforcement source, reported the investigation centers around Brown's boyfriend, Nick Gordon, and injuries Brown allegedly suffered before she was found unconscious. Police are investigating the possibility an altercation occurred about an hour before she was found.

Maxwell Lomas, the family friend who discovered Brown, met with Gordon in Brown’s residence the morning she was found, the website said. After an hour of being in the apartment, Lomas found her after an employee from a cable provider arrived at the residence and needed access to Brown's bedroom. Lomas screamed for Gordon who then entered the room and performed CPR.

TMZ reported police have not revealed what injuries Brown suffered or why they think something occurred before she was found. The site said, however, its sources confirmed a violent relationship between the couple. TMZ said Lomas claimed Gordon allegedly cleaned up the home to remove blood stains and has hired legal representation.