The Norwegian swimming federation says world champion Alexander Dale Oen has died during a training camp in Flagstaff, Arizona. He was 26.
Federation President Per Rune Eknes said on Tuesday that Dale Oen died after suffering a cardiac arrest.
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. He was taken to the Flagstaff Medical Center.
Hospital spokeswoman Starla Collins confirmed the death, but did not provide further details.
Dale Oen won the 100 breast stroke at the worlds in Shanghai last July and took silver at the 2008 Beijing Olympics. He was one of Norway's top medal hopes for the London Games.