Authorities are still probing the cause of world champion swimmer Alexander Dale Oen\'s death after an initial autopsy was inconclusive, authorities in Flagstaff, Arizona said. \"An autopsy on Alexander Dale Oen was performed by the Coconino County Medical Examiner\'s Office on Tuesday. Following the initial examination, the cause of death is pending,\" Barbara Worgess, the chief health officer for the county, said in a statement. \"Additional tests are being conducted.\" The medical examiner\'s office said the initial autopsy \"revealed no anatomic cause of death and no trauma associated with the death\". Norway\'s Dale Oen, 26, died in Flagstaff, where he was training at altitude with team-mates in preparation for the London Olympics. The reigning 100m breaststroke world champion was found collapsed in a shower at a swimming pool by team-mates on Monday, the Norwegian swimming federation said. The team doctor tried to resuscitate him, as did paramedics who arrived within minutes to take him to hospital. \"We routinely run additional tests to help determine cause of death and we are consulting with a cardiovascular pathologist,\" Worgess said of the ongoing investigation. \"Final test results may take eight weeks or longer to be completed.\" Dale Oen became Norway\'s first swimmer to win an Olympic medal when he won the silver in the 100m breaststroke in the 2008 Games in Beijing. He had been tipped as one of Norway\'s best chances of a medal at the London Olympics in July.