The initial autopsy on Bobbi Kristina Brown released Monday showed she did not suffer significant injuries that caused her death.
The autopsy also did not find any medical conditions that might have contributed to the 22-year-old's death, according to the Fulton County Medical Examiner's office in Georgia.
Brown, the daughter of the late Whitney Houston and Bobby Brown, was found unresponsive in a bathtub of her Georgia home on Jan. 31 and suffered irreversible brain damage, according to her family.
The Fulton County Medical Examiner's office said subpoenas have been issued to help find more information about her death, and additional testing will be performed.
A death certificate will not be completed until "all test results are completed and all investigative, medical, and other documentary records are received and thoroughly reviewed," which could take several weeks, according to the medical examiner's office.
Fulton County District Attorney Paul Howard said the ultimately-fatal incident is still under investigation.
Nick Gordon, who has been described as Brown's boyfriend and husband, has been accused in a lawsuit of causing "life threatening bodily harm and damages" to Brown.
Earlier, the medical examiner's office said in a statement that the nearly six months between the day Brown was found in the tub and her death "will complicate reconstruction of the events surrounding her initial unresponsiveness."
Bobby Brown said he was "numb" in a statement released by his lawyer Monday.
"Krissy was and is an angel," he said. "My family must find a way to live with her in spirit and honor her memory. Our loss is unimaginable."