Yahoo has reported that Bobbi Kristina Brown was using heroin and other drugs before she was found face down and unresponsive in her bathtub on January 31.

The allegation, which comes from a People source, is that the 21-year-old “regularly” used heroin, cocaine and Xanax , and also drank heavily in the months leading up to the incident .

People cites one source as saying that Brown had been “in and out” of rehab since her mother’s death on February 11, 2012. The addiction, the source alleges, was fueled as she was “distraught” over the upcoming anniversary of Houston’s death.

Brown was placed in a medically induced coma and put on a ventilator after being taken to hospital. US media reports are that she underwent a tracheotomy this week, in order to provide another air passage.

Further reports are that Brown’s condition has not changed but removing the breathing tube was a standard course of practice to avoid infection.

Family members have reportedly said that Brown, the only child of singers Bobby Brown and Houston, is fighting for her life at Emory University Hospital in Atlanta.

Police are allegedly treating the case as a criminal investigation and have been questioning people about the circumstances leading up to Brown being found in the tub.

tagged in Bobbi Kristina