Police have revealed the swimmer believed to have been taken by a shark on the NSW South coast is 63-year-old Tathra resident Christine Armstrong.
Police Inspector Jason Edmunds told the ABC that Mrs Armstrong’s husband Rob was part of the group of five swimming with her when she turned back and was attacked.
‘‘He did see a shark he described as three or four metres long and it was very big but what type of shark I wouldn’t speculate,’’ he said.
Mrs Armstrong's family have released a statement saying she had been swimming at Tathra for many years.
"Chris was very loved by many people. She has been swimming at Tathra Beach for 14 years and was an experienced and committed member of the surf club," the statement read.
"She was a senior surf club trainer for many years and swimming brought her much joy and many friends. She will be sadly missed by all who loved her, especially by Rob, her husband of 44 years."
Authorities are still searching the ocean off the NSW south coast town for the woman's body and the shark.
The search for Mrs Armstrong was called off about 5pm (AEDT) due to poor weather.
It’s expected to resume at first light on Friday.
A police spokesman said if the body has sunk below the surface it could take days before it resurfaced.
The tragedy comes just two years after Tathra Surf Life Saving Club's then-surf boat captain Sharon Clarke warned shark fishing off the local wharf was attracting sharks to the area.
The woman was on her regular morning swim with a group of people between Tathra Wharf and Tathra Beach about 8.20am when she was killed.
Police said the woman - who is believed to be member of the Tathra Surf Life Saving Club - had turned back from the group and was swimming on her own when she was attacked.
Mrs Armstrong's husband Rob was part of the group of five swimmers, who saw a large shark 3 to 4m long.
Another man on the rocks at the time said he saw a shark in the area.
Westpac Lifesaving operation manager Craig Roberts said the Lifesaver 3 helicopter had been unable to spot the body and police stood down the helicopter at 12.42pm.
Police initially gave the helicopter a search area north and south of the Tathra headland.
Police have not confirmed reports that remains had been found.
Tathra Beach has been closed following the fatal attack.
Police said the group of swimmers were treated for shock and were under general observation.
"Emergency services are doing what they can for them but naturally they're shocked and horrified by what's occurred," said a police spokesperson.
Mr Roberts said the helicopter had dropped dye into the water to determine the flow of the tide.
Two surf lifesaving vessels, along with local fishing vessels under the co-ordination of NSW Water Police, were also looking for the shark.
Tathra residents have spoken of the loss of one of their own.
Bega District News editor Ben Smyth is on the scene, and said it came as a shock to locals.
Tathra woman Molly Carroll, who was on the beach just minutes before the fatal attack, described the scene as "eerie".
"It is a bit of a shock," she said.
"It is a bit of an eerie feeling."
Bob Armstrong has spent 60 years in Tathra and has had a long association with the local surf lifesaving club.
He said that in the 1950s, the club patrolled around the cliffs and had seen sharks in the area but this was the first attack in the area he knew of.
The alert went out shortly after 8.40am on Thursday, with police, surf lifesavers, the ambulance service and the Lifesaver 3 helicopter called to the scene.
It is understood Department of Primary Industries fisheries officers will conduct an investigation at Tathra once the shark attack is officially confirmed.
The woman's death is the second fatal shark attack in NSW waters in five months.
Zac Young, a 19-year-old body boarder died, after he was attacked by a tiger shark at Campbell's Beach north of Coff's Harbour on November 20 last year.
Two other men were bitten by sharks in separate incidents in the past 12 months, but neither were seriously injured.
- Sydney Morning Herald