Dale Oen was the reigning 100m breaststroke champion after winning gold in Shanghai last year. Photo by EPA/BGNES
Norway's world swimming champion Alexander Dale Oen, has died suddenly in the US, aged 26, the country's swimming federation announced.
The federation said in a statement that the 100-meter breast stroke world champion was found collapsed on the floor of his bathroom on Monday after training in Flagstaff, Arizona. He was taken to the Flagstaff Medical Center.
Federation President Per Rune Eknes said Dale Oen had suffered a cardiac arrest.
Norwegian media cited friends as saying he had appeared healthy earlier.
Dale Oen was the reigning 100m breaststroke champion after winning in July 2011 gold medal in this event at the Fina World Championships in Shanghai.
His gold medal in Shanghai came shortly after Anders Behring Breivik murdered 77 people in Oslo and the island of Utoeya and at the time he described the events at home as a motivation for him. "We can't let this guy ruin the future for us," he said.