Beaches in the Australian city of Sydney have reopened to swimmers after being closed earlier this week when thousands of mysterious black tar-like balls washed up, causing health concerns.
Officials say tests have shown that the balls are formed from chemicals similar to those found in cosmetics and cleaning products, but it is still unclear where they come from.
Eight beaches, including Bondi – the city's most famous – were closed and a major clean-up ordered amid fears the black deposits were toxic.
New South Wales Environment Minister Penny Sharpe said the investigation is continuing to determine the source of the pollution and who is responsible.
The state maritime authority said the balls are not highly toxic to humans but should not be touched or picked up.
“Following advice from the Environment Protection Authority, we can now confirm that the balls consist of fatty acids, chemicals similar to those found in cleaning and cosmetic products, mixed with a little fuel oil,” said Mark Hutchings, executive director of New South Wales Maritime. .
The New South Wales Environment Protection Authority (EPA) said laboratory tests were continuing to try to determine where the balls came from, Reuters news agency reported.
“It's still a bit of a mystery and it may take a few more days to determine its origin,” said Stephen Beaman, executive director of the EPA.
The tar balls were “not harmful when left on the ground, but should not be touched or picked up,” Australian broadcaster ABC said.
“If you see these balls, report them to a lifeguard. If you or your family accidentally touch one, wash your hands with soap and water or baby oil.”