Rescue crews have returned to base as harsh weather continues to delay the search for an aircraft missing in Antarctica.
The missing Twin Otter plane's emergency locator beacon was activated late last night and the New Zealand Rescue Coordination Centre, coordinating the search for the aircraft, is yet to make contact with the three Canadian men onboard
New Zealand Search and Rescue officials say the weather is not set to get any better.
"Weather conditions are extremely challenging," said Search and Rescue mission co-ordinator John Ashby.
"There are winds of 90 knots at the site," he said.
"During the next twelve hours we're predicting similar conditions, more snow and visibility down to about 200 metres so until it clears, we really can't move any resources into the area."
The plane was en route to the Italian base in Terra Nova Bay when around 10pm last night its emergency locator beacon was activated, around 670 kilometres from McMurdo Station.
The beacon is transmitting from the Northern end of the Queen Alexandra Range, within New Zealand's Search and Rescue Region.
The state of the aircraft or the crew is not known.
The Twin Otter plane is operated by Canadian company Kenn Borek Air, and Maritime New Zealand says the crew on board is very experienced. Ashby said the plane was equipped with enough survival equipment, including mountain tents, to last five days.
Ken Borek Air's website says it has been heavily involved in Antarctic operations for the past 27 years and that safe operation is its most important commitment.
Frustrated rescue co-ordinators are hoping for a break in the weather, with crews and paramedics on standby to enter the crash site as soon as the weather allows.