The mysterious balls that forced the closure of several beaches in Sydney last week were found to contain saturated acids, E. coli and faecal bacteria, authorities say. Sydney's Northern Beaches council said it has sent the debris to the New South Wales Environment Protection Authority (EPA) for further analysis.

Nine beaches in Sydney, including well-known Manly beach, were closed to bathers on Tuesday after small white and grey balls of debris washed up on the shores at the height of the summer holiday season.

Workers have cleaned up and reopened seven of nine northern Sydney beaches after mysterious balls washed ashore.

Months after mysterious black balls forced the closure of some of Sydney's most famous beaches, small marble-like debris has begun washing up on the city's shores again. The balls - this time grey or white in colour - have prompted councils to shut nine beaches, including popular Manly and Dee Why, while authorities investigate.

Several popular beaches in Sydney, including Manly and Dee Why, were closed recently due to the sudden appearance of mysterious small balls washing ashore. Also read Mysterious Balls Close Sydney Beaches Once Again as Authorities Investigate Now the Northern Beaches Council confirms that the balls contained saturated acids,

The contents of mysterious grey balls washed up on Sydney’s Northern Beaches have now been identified after nine beaches were closed due to the pollution spheres.