Obviously nowhere near as big as some of the fish you guys have mentioned but here's a passage from one of no no no's articles on Middle Harbour. Great reading!
Back in the '50s, the navy jetty off Balmoral earnt it self a formidable reputation for enormous, tackle breaking fish living amongst its pylons. Everybody assumed that they were kingies, as big kings were occasionally spotted cruising around and taking big live baits. But despite attempts by naval personnel with all manner of obscenely heavy tackle including venetian blind cord on a trailer winch and ski rope tied to a army forklift, nothing was ever positively identified. In 1968, the navy jetty was opened to the public, but even experienced anglers with more modern game tackle were unable to land these mystery fish. In the mid-seventies, a guy by the name of Chris Ward turned up with the latest in stand-up game tackle. This included a gimbal bucket and all manner of clips and harnesses. The reel was loaded with venetian blind cord and the drag cranked up to the max. It wasn't long before Chris's big bait was eaten but immediately Chris realized he had made a big mistake. The drag on the reel would not give and as he was heavily strapped to the rod he was unable to let go. To the horror of the onlookers, Chris was dragged across wooden planks and into the water. The body was never recovered and after a court hearing the jetty was again closed to the public on liability grounds.
In 1977, the mystery was finally solved when a prawn trawler working off Gladesville entangled a 376lb black cod (now fully protected) in its net. The cod was lying on the deck and one of the trawler men noticed heavy cord coming from the fish's mouth and leading into the water. The cord was retrieved to revealed a hideous discovery. A rod, reel and gimball harness containing the skeletal remains of a human torso rose up out of the water. The head arms and legs were missing so police were unable to ID the remains but decorative binding on the lower section of the custom built rod butt spelt out the word 'Mango'. Chris Ward originally came from the Queensland town of Bowen where he had grown up on his fathers Mango farm. A quick check with his old school mates revealed that 'mango' had indeed been his nick name.