Exclusive: Fat, oil and grease built up in sewerage pipes before being dislodged by heavy rain and ejected from Malabar outfallFollow our Australia news live blog for latest updatesGet our breaking news email, free app or daily news podcastA secret report reveals the likely source of the fatberg balls that closed a raft of Sydney beaches last summer – with most coming from the deepwater ocean outfall at Malabar.The partly redacted scientific report, obtained by Guardian Australia under freedom of information laws, points to a combination of heavy rains and a buildup of fats, oils and greases as the likely cause of the “poo balls” being discharged from outfalls at Malabar, Bondi and North Head. Continue reading...