The incident occurred at approximately 10 a.m. on Sunday morning when a 60-year-old man from Queensland was surfing at Salt Beach, South Kingscliff, in the Australian state of New South Wales, just over a one-hour drive south from the city of Brisbane.
Witnesses say that the man was attacked by a 3-meter-long (10 feet) shark. The man has yet to be formally identified.
Police say that several other surfers came to his aid and were able to fight the shark before helping him to shore.
The victim was treated for serious injuries to his left leg but died at the scene.
“Officers from Tweed/Byron Police District will be liaising with the Department of Primary Industry to investigate the circumstances surrounding the death,” the New South Wales Police Force said in a statement on social media.
Authorities have now closed to the beaches between Kingscliff and Cabarita for 24 hours and the area has been cleared of swimmers and surfers by officers from the Marine Area Command and the local Surf Livesavers.
In January, a 57-year-old diver named Gary Johnson was killed near Esperance off Western Australia's coast and in April, a 23-year-old Queensland ranger named Zachary Robba was killed off the coast of North West Island on the Great Barrier Reef.
ABC News' Christine Theodorou contributed to this report.