The death of George Floyd has been declared a homicide following an official post-mortem examination.
A medical examiner's finding confirms the same conclusion of the independent autopsy that was also released on Monday, but there are key differences over the cause.
The 46-year-old suffered a cardiac arrest while being restrained by police in the US city of Minneapolis, the official report found.
It listed Mr Floyd's cause of death as "cardiopulmonary arrest complicating law enforcement subdual, restraint, and neck compression".
A video showing a white police officer continuing to kneel on Mr Floyd's neck even after he pleaded he could not breathe has reignited deep-seated anger over police killings of black Americans.
The official post-mortem examination of Mr Floyd recorded evidence of heart disease and recent drug use.
It found that he suffered the cardiac arrest "while being restrained by a law enforcement officer" on May 25.
Two doctors who carried out an independent autopsy of Mr Floyd and two attorneys for the family said that he had no underlying health conditions that may have contributed to his death.
Dr. Allecia Wilson of the University of Michigan, one of the two forensic doctors who performed the independent autopsy, said the evidence pointed to homicide by "mechanical asphyxia" - meaning from some physical force that interfered with oxygen supply.
The original criminal complaint against the police officer who pinned Mr Floyd with his knee cited the medical examiner's office when it said it found no findings of strangulation.
Carolyn Marinan, a spokeswoman for Hennepin County, did not confirm any reversal, saying only that Monday's press release were the "final findings."
Bystander video showed Floyd pleading to be let up and saying repeatedly that he couldn't breathe as police officer Derek Chauvin pinned Mr Floyd to the ground for nearly nine minutes.
Two other officers applied pressure with their knees to Mr Floyd's back.
Chauvin, who is white and has been fired from the Minneapolis police department, was hit with third-degree murder and manslaughter charges last week.
But Dr Michael Baden, who took part in the independent autopsy at the behest of Floyd's family, said that the two other officers' actions also caused Mr Floyd to stop breathing.
"We can see after a little bit less than four minutes that Mr Floyd is motionless, lifeless,” Dr Baden said, adding he found no underlying health conditions in Mr Floyd that caused his death.
Dr Baden has worked on several high-profile cases, including the 2014 death of Eric Garner, a black man who died after being choked by police in New York City.
Agencies contributed to this report