The crew on board the stricken Russian fishing vessel Sparta have found a second hole in the bow of the boat.
The 48-metre vessel, which has 32 crew, has been stranded off the Antarctic ice shelf since 16 December when its hull was pierced by ice.
The New Zealand Rescue Co-ordination Centre launched a rescue mission after the crew of the Sparta sent out a mayday call on 16 December from near the Antarctic ice shelf, in the Ross Sea, nearly 4000 kilometres south east of New Zealand.
The Korean icebreaker Araon arrived alongside the Sparta on Boxing Day and pumped fuel oil from the fishing vessel to raise the bow and expose a 30 centimetre hole, so it could be repaired.
The materials needed for the repairs were dropped to the crew by a New Zealand hercules crew.
Search and Rescue Mission Coordinator Mike Roberts says since the bow was raised above water level on Monday a second hole has been discovered on Sparta's bulbous bow, but this has only caused localised flooding.
Mr Roberts says repairs to the original 30 centimetre hole are going well and a cement box will be secured to the inside of the hull which will make the vessel seaworthy.
Mr Roberts says the Araon is expected to remain alongside Sparta while repair work is made and it will then escort her to an ice-free area of open ocean.
Both vessels are expected to leave their current location at midnight on 28 December.