The debris forced the closure of nine beaches

Months after mysterious black balls forced the closure of some of Sydney’s most famous beaches, tiny marble-like debris is washing up on the city’s beaches again.

The balls – this time gray or white in color – have prompted councils to close nine beaches, including popular Manly and Dee Why, while authorities investigate.

Eight beaches, including Bondi, were closed for several days in October and a major clean-up was carried out after thousands of black deposits began to appear on the beach.

Tests by authorities confirmed the balls were likely caused by a sewage leak.

Northern Beaches Mayor Sue Haynes said the close balls “could be anything”, Guardian Australia said.

“We don’t know what it is at the moment and that makes it even more worrying,” she said.

“Obviously there’s something that flows or drops…there’s something that floats and is thrown.”

The Northern Beaches Council said in a Facebook post on Tuesday that they had been warned by the New South Wales Environmental Protection Agency (EPA) about the fresh debris.

The agency and the council plan to collect the findings and plan to test and examine other beaches in the area.

Anyone who saw the balls is urged to contact authorities, the council added.

Although widely reported to be “tar balls,” the wreckage in October was found to contain everything from oil and soap scum molecules, blood pressure medication, pesticides, hair, methamphetamine and animal drugs.

Scientists look at fat, oil, and grease stains — often called fatbergs — that commonly form in the sewage system.

However, Sydney Water reported there were no known problems in the city, and officials still do not know the source of the material, leading some to express concern about the safety of the city’s beaches.

Greens state politician Sue Higginson said in a statement in December: “The EPA cannot explain the source of the human waste that is causing the fat fracturing and cannot assure the public that Sydney’s beaches are safe to use.”