Some of Sydney's most popular swimming spots including Coogee and Gordons Bay beaches will remain closed after thousands of mysterious balls washed ashore. Preliminary test results identified the dark spheres as 'tar balls' – which are formed when oil comes into contact with debris and water, usually as a result of oil spills or seepage. Addressing reporters on Thursday, Randwick council mayor Dylan Parker said the beaches will stay closed while further investigations are carried out by government agencies. Bondi, Tamarama and Bronte beaches had also closed 'out of precaution', Waverley council said in a statement on Thursday
