A baffling tar ball emergency that closed four major beaches in Sydney's eastern suburbs appears to be over.
Background: Beaches in Sydney's eastern suburbs were closed after a deluge of "tar balls" began washing up, prompting a major clean-up.
The remaining beaches closed to bathers at Coogee, Maroubra and Clovelly have been cleared to reopen on Saturday after Bondi and several others reopened on Friday.
Key quote: "It is still somewhat of a mystery and may take a few more days to determine origin." - NSW Environment Protection Authority executive director Stephen Beaman.
What else to know: The cause of the tar ball emergency remains unknown, but NSW Maritime executive director Mark Hutchings said that based on health advice, the substance was not highly toxic to humans.
Tar balls are formed when oil comes into contact with other debris and water, usually as a result of oil spills or seepage.
What happens next: The NSW Environment Protection Authority is still examining the balls and conducting tests.
Beachgoers have been told to let lifeguards know if they see any tar balls.