A Las Vegas coroner investigating the mysterious death of Port Adelaide football star John McCarthy said that there are no suspicious circumstances surrounding the tragedy. However, police are still waiting for the autopsy and scouring the CCTV footages for clues.

Tragic news in the sports world as AFL player John McCarthy fell 9m to his death from the roof of the Flamingo Hotel and Casino.

Investigators are waiting for the full autopsy report, including toxicology tests, before determining the exact cause of death.

Security staff of the Hotel called and reported that a man had fallen from the roof of the hotel and onto the paved driveway. McCarthy was transported to a nearby hospital but was pronounced dead few minutes later.

It is still unclear whether the AFL star committed suicide by jumping off the roof or it is a plain accident. Relatives and friends of the athlete declined for comment.

The circumstances behind the passing of McCarthy remain under investigation but Mr Murphy said the 22-year-old was alone at the time.

"There is nothing that appears to be suspicious in nature, such as there was no interaction in nature between two humans on this roof," he said.

The 22-year-old Port Adelaide player had arrived in Las Vegas on an end-of-season trip less than 24 hours earlier.

"The Coroner's Office is working with the family to return the decedent to his home country and family," read the statement, from the Clark County Coroner and Medical Examiner's Office. An autopsy is being conducted today. The cause of death may take weeks to determine, pending the results of the autopsy and the return of toxicology and other laboratory reports," the coroner said in a statement.

Collingwood Magpies players will wear black armbands to honor McCarthy during Saturday night's AFL final against the West Coast Eagles, club president Eddie McGuire said.