Australian teen Jay Muscat was spearfishing with a friend at Cheynes Beach in Western Australia last Monday, when a shark attacked and killed him. Muscat, 17, was the second victim of a shark attack in Australia this month.

"It is believed a shark approached both of them, and at that time the deceased appears to have received a shark bite injury," local police said.

Two weeks ago, Daniel Smith was also spearfishing at the Rudder Reef off the coast of Port Douglas, when a shark attacked and killed him. Smith was 18.

The shark is believed to be a great white, according to experts. It should be around 13 to 16 feet long, Carlo Vittiglia, State Fisheries Department spokesman said.

The surviving diver and a local fisherman reported to have seen a great white shark; the bite on the deceased's leg also indicated the attacker to be a white shark.

Local officials are currently on the hunt for the said shark and closed the beach to prevent more attacks from occurring.

"This is obviously an extremely tragic event for all the families involved and our sympathies go out to those particular families," he said.

"We're not looking to speculate at this stage on any of the details."

Fletcher said Fisheries staff had been unable to confirm reports from another fisherman that he had seen a white shark in the area, but he said the description provided by the surviving diver, coupled with the size of the bite on the deceased boy's leg, indicated it was a white shark.

"From the reports and the advice we have about the injuries it appears it was a very large shark, probably four to five metres, and probably a white shark," Dr Rick Fletcher Acting Director General for the Department of Fisheries told the press.

Fletcher further explained that the deceased teen was a large person and his leg suffered a large bite, which led them to a conclusion that a huge shark was behind the attack. He also said that they won't be making any speculations as to what kind of shark attacked Muscat.

Three fatal shark attacks were reported this year in Australia.