Sydney's water contamination crisis -- its second in a month -- worsened Friday, with authorities extending health warnings and urging residents to boil tap water before drinking it.
Organizers of the 2000 Olympics in Sydney said the scare threatened to taint the city's international reputation.
Test results have varied widely. Late Thursday, they showed extremely high levels of the dangerous parasites cryptosporidium and giardia. Tests Friday, however, showed no signs of either, said Michael Reid, director-general of the New South Wales state health department.
Health warnings will not be lifted until a series of tests shows the water is safe.