WELLINGTON: Three people died and another three were missing after a New Zealand chartered fishing boat with a crew of 51 sank in icy waters in the Southern Ocean early Wednesday, rescuers said.

Forty-five survivors had been recovered from life rafts and three people including the ship`s master were unaccounted for, New Zealand search and rescue coordinator Mike Roberts said.

"We have so far recovered five life rafts but have been advised there was a sixth life raft on board. We remain hopeful of locating the three missing men," Roberts said.

The nationalities of the crew on the South Korean-flagged vessel Oyang 70 were listed as Korean, Indonesian, Filipino and Chinese.

The weather in the area was described as extremely cold. Fog, hampering visibility, was expected to lift.

New Zealand`s Rescue Coordination Centre received an alert from the positional indicator beacon on the 82-metre (270-feet) trawler at 4:40 am (1640 GMT Tuesday).

Soon after, a mayday call was relayed by a nearby fishing vessel which reported the Oyang 70 had sunk about 400 nautical miles east of the southern New Zealand city of Dunedin.

Roberts said five fishing vessels were at the scene assisting with the search and a New Zealand Air Force Orion was conducting an aerial sweep of the area.

Rescuers were not prepared to speculate on what caused the sinking but said the vessel had gone down very quickly.

Hyun Choi from Southern Storm Fishing, which has chartered the Oyang 70 for more than 10 years, told Radio New Zealand News the ship worked in the Southern Ocean once a year.

BDST: 9:53 HRS, August 18, 2010