Bobbi Kristina Brown's initial autopsy showed no obvious underlying cause of death or any significant injuries.
The information of "no evidence found" was stated by the Fulton County Medical Examiner, TMZ.com reported.
Notably, the investigation might help late singer Whitney Houston and Bobby Brown's deceased daughter's boyfriend Nick Gordon, who's been under suspicion, to get free from police enquires.
Bobbi, who was found face down in a bathtub back in January and had been in medically induced coma for 7-months, died recently aged 22.