Footage of the shark that is thought to have made the attack
An Australian father is missing, feared dead, after reportedly being attacked by a shark while swimming with his son.
Brian Guest, 51, was in the ocean south of Perth, Western Australia, when locals reported "something pretty violent" out in the water.
His 24-year-old son raised the alarm as rescuers began a search for Mr Guest, described as an experienced swimmer and diver who knew the area well.
Australia has had one other fatal shark attack in 2008, off the eastern coast.
Surfer Peter Edmonds, 16, was taken by a shark off the coast of New South Wales at Ballina in April.
'Respect for nature'
Witnesses and officials admitted that the latest incident, which happened near Rockingham, to the south of Perth, bore the hallmarks of a shark attack.
Mr Guest and his son were reportedly snorkelling for crabs in familiar waters when they were attacked.
"There was lots of talk among witnesses at the incident location about seeing fins in the water but we can't yet say whether there was definitely a shark out there, though in all probability that's what it is," Mark Valentine, a local police inspector, told the Australian Associated Press.
"Something very traumatic and pretty violent has happened there and we are treating it as a probable shark attack," he added.
Other witnesses reported that a shark had been spotted in the area during the search.
A family friend said Mr Guest's son had been swimming close to his father at the time of the attack although he did not see it happen. He quickly ran ashore to raise the alarm.
He said the family was assuming the worst.
''It's a shock loss for the family," Steve Kent told Australian reporters. "He was a loving father and husband who appears to have been taken by a shark.''
He added that Mr Guest, who worked in the banking industry, would not have wanted the shark to be hunted and destroyed.
"[He's spent] many, many years diving and fishing and [has] a very deep respect for the water and he knows the dangers of being in the water," Mr Kent said.
"It's nature and we should pay respects to nature and nature's ways."
Police are warning those using beaches around Perth to be careful when swimming.
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