Ross Land/AP Photo

A New Zealand fisherman was one of many witnesses to a rare, deadly shark attack on a man swimming 200 yards offshore, west of Auckland.

"He just shouted out 'shark,' and the next minute we saw him rolling around," Pio Mose, the fisherman who saw the attack, said. "There was blood everywhere on the water. First, there was one shark, but then after five or six minutes there were three sharks all over him, rolling him around."

Mose said the victim raised his head as the first shark attacked him, and Mose and others onshore shouted to the victim.

"We yelled out at him to swim over to the rocks, and he raised his hand up," Mose said. "The next minute he went down, the shark pulled him down."

Rescue teams raced into the water in a desperate attempt to reach the swimmer. Tim Jago of the Life Saving Club said that when his team found the body, the sharks were still there.

"The police managed to distract the shark while we extracted the person from the water," Russell Clarke of the Westpac Rescue Helicopter Paramedic team said.

Police in boats took aim at the shark.

"My guy took a firearm, discharged his firearm at the shark," said New Zealand Police Inspector Shawn Rutene. "We do not know if he hit the shark, but the shark rolled and disappeared."

But it was too late. The victim, a man in his 40s, who has not been named, was dead. Rutene said that the man's family was very upset and distraught.

Witnesses said the shark was huge. Experts who screened footage said the shark may have been more than 10 feet long.

"I think it's most likely to have been a great white shark in this instance," Craig Thorburn, a marine biologist, said. "In reality, the only sharks around New Zealand that ever really take on prey items as big as a person would be a great white."