The medical examiner's office in Minnesota has released its full 20-page autopsy report on George Floyd's death.

Bystander video showing Minneapolis police officer Derek Chauvin pressing his knee on Floyd's neck as he restrained him, ignoring Floyd's "I can't breathe" cries until he eventually stopped moving, has sparked protests in the United States and around the world, some violent.

The 20-page report released by the Hennepin County Medical Examiner's Office came with the family's permission and after the coroner's office released summary findings Monday that Floyd had a heart attack while being restrained by officers, and classified his May 25 death as a homicide.

His official cause of death is listed as "cardiopulmonary arrest complicating law enforcement subdual, restrain, and neck compression", which in plain English means the knee pressing into his neck resulted in cardiac arrest.

The examiner found Floyd had a number of injuries, including "cutaneous blunt force injuries" on his forehead, face and upper lip, "mucosal injuries" inside his lips, "blunt force injuries" on his shoulders, hands, elbows and legs and "patterned contusions of the wrists", which were caused by handcuffs.

He suffered from three underlying conditions – severe "arteriosclerotic heart disease", "hypertensive heart disease" and an "incidental" tumour on the left side of his pelvis.

Floyd had also contracted the coronavirus at some point. The report by Chief Medical Examiner Andrew Baker spelled out clinical details, including that Floyd had tested positive for Covid-19 on April 3 but appeared asymptomatic. The report also noted Floyd's lungs appeared healthy but he had some narrowing of arteries in the heart.

The county's earlier summary report had listed fentanyl intoxication and recent methamphetamine use under "other significant conditions" but not under "cause of death." The full report's footnotes noted that signs of fentanyl toxicity can include "severe respiratory depression" and seizures.

Minnesota Attorney General Keith Ellison today upgraded charges against Chauvin to 2nd-degree murder, and also charged the three other officers on the scene with aiding and abetting.

Floyd family attorney, Ben Crump, earlier decried the official autopsy — as described in the original complaint against Chauvin — for ruling out asphyxia. An autopsy commissioned by the Floyd family concluded that he died of asphyxiation due to neck and back compression.