Port Adelaide footballer John McCarthy has died while holidaying in Las Vegas.

The Power has confirmed the death of the 22-year-old in a fall from a building in the US resort town. Details surrounding the fall are still unclear but there were witnesses to the incident.

McCarthy was one of 11 Port players holidaying together in Vegas and staying at the Flamingo complex, part of the Caesars chain and the oldest resort on the Las Vegas strip.

The players left Australia on Saturday after the club's best-and-fairest dinner on Friday night.

Port Adelaide chief executive Keith Thomas faced the media in Adelaide late today and said the club was devastated over the young player's death.

He said the club was informed this morning about a "fatal accident" involving one of their players.

"It's our understanding that at the time of his death he wasn't with any other players," Thomas said.

The other players are making plans to return from the United States as soon as possible. A grief counsellor has been at the club's Alberton headquarters helping teammates cope with the news.

Thomas said it had been a great shock to the club. "It's devastating news. He's a young fella, he's 22 ... It's a major, major setback, emotionally."

A hotel spokeswoman said in a statement that the man was found on the hotel's south driveway. He was unresponsive, she said.

"He was transported to the University Medical Center of Las Vegas, where he was pronounced deceased," said the spokeswoman, Debbie Munch.

"Nevada's Clark County Coroner's Office is investigating and is the point of contact for further details.''

McCarthy's death was not immediately confirmed by the club or police today because his friends and family were still being informed about the death.

The club's player operations manager Peter Rohde is travelling to Las Vegas to assist distraught teammates of the player.

''The club is in contact with members of the travelling group and is working with US authorities while investigations continue ... The club has also made contact with its other players still in Australia,'' a statement released earlier by Port Adelaide said.

A Victoria Police spokeswoman said: "Victoria Police is aware of an incident involving a Victorian man in Las Vegas. As it is not a Victoria Police investigation, it would be inappropriate to comment further".

A spokeswoman for the Department of Foreign Affairs said the department was in contact with US authorities about the incident.

"We are aware of reports an Australian man has been involved in a serious incident in Las Vegas," she said.

''Australian consular officials are seeking further details from US authorities.''

Las Vegas police refused to comment on the incident, saying they had been ''inundated'' with calls and would comment in the morning, US time.

McCarthy moved to Port Adelaide at the end of the 2011 season after four seasons at Collingwood.

- AAP