SYDNEY, Nov 8 — Australian scientists have identified the source of dark, sticky blobs that recently appeared on several Sydney beaches, according to the BBC.

Initially thought to be tar balls, researchers now confirm these deposits are a repulsive mix of human faeces, cooking oil, chemicals, and illicit drugs.

Eight beaches, including Bondi, were closed from 16 October for a clean-up after the discovery, BBC reported.

While New South Wales officials initially suspected a mix of fatty acids, fuel oil, and cosmetic chemicals, further analysis pointed to a probable sewage spill, though the exact source remains unknown.

According to the report, each blob varied slightly in composition, with a hardened exterior due to accumulated sand and minerals, and a soft core.

Researchers found traces of cooking oil, soap molecules, blood pressure medication, pesticides, hair, methamphetamine, and veterinary drugs within.

Lead investigator Associate Professor Jon Beves from the University of New South Wales described the odour as “worse than anything you’ve ever smelt.”

Professor William Alexander Donald noted that the blobs resemble “fatbergs” found in sewer systems, with drugs and industrial chemicals pointing to sewage and urban waste as likely sources.

BBC reported that Sydney Water has confirmed there are no current issues with the city’s waste systems.