Authorities are investigating the death Sunday of Bobbi Kristina Brown, the daughter of Whitney Houston and Bobby Brown, as a homicide, TMZ.com reports. The 22-year-old died after months of hospitalization, as we reported previously.

“TMZ has learned it’s now officially a homicide investigation,” the website reports. “Law enforcement sources tell us, both the D.A. and the cops are treating the mystery as foul play, and Bobbi Kristina’s boyfriend, Nick Gordon, continues to be a person of interest.”

Law enforcement officials have suspected foul play from the beginning, according to TMZ, which notes that it reported back in February that an active criminal investigation was under way.

The website says first responders spotted injuries on Brown’s body back on Jan. 31 when they responded to a call after Brown was found unresponsive in a bathtub. She was hospitalized at that time and remained in hospitals and rehab centers for the rest of her life, including being in a medically induced coma for some time.