The Japanese surfer was reportedly pulled out of the water by a group of surfers at Shelly Beach in the New South Wales town of Ballina on Monday.
The Japanese man was killed after both his legs were apparently bitten off by what local Detective Inspector Cameron Lindsay described as a "very large shark."
He was also quoted as saying that "despite some really heroic efforts" the 41-year-old victim died at the scene from a massive loss of blood.
The town of Ballina is located 12 miles, or 20 kilometers, south of Seven Mile Beach, where surfer Jabez Reitman was attacked by a shark on Sunday.
Beaches in the area have swiftly been closed, with experts currently trying to determine whether the two attacks were carried out by the same shark.
Recent years have seen several shark attacks off Australia's beaches, including an attack in Eastern Australia's Byron Bay in September 2014, in which a 50-year-old Briton died. The country witnessed four shark-related fatalities last year, two in 2013 and two in 2012.
