Rescue ships headed to a Russian liner trapped by heavy sea-ice near Antarctica won't reach the stricken vessel until at least Friday night, federal authorities say.
There are 50 tourists, scientists and explorers and 20 crew on the Russian ship MV Akademik Shokalskiy, which is on a Spirit of Mawson voyage along the edge of Antarctica.
Three ice-breaking ships have been sent to assist in the remote location more than 1500 nautical miles south of Hobart, after a distress call was sent on Christmas morning.
Australian Maritime Safety Authority (AMSA) spokeswoman Andrea Hayward-Maher said the ships still had some way to travel before reaching the trapped vessel.
"It is literally a very, very long way away," Ms Hayward-Maher told Macquarie Radio.
"The first vessels that have been tasked to respond wont' be on the scene until the earliest late tomorrow night."
She suspected "fast flowing ice" had caused the vessel to get stuck.
"The ocean is inherently unpredictable, and if there's different currents ... these sorts of things can happen," she added.
The Australian Maritime Safety Authority has previously said that those onboard the ship are not in danger.
Its voyage is part of a research expedition to commemorate the centenary of Douglas Mawson's exploration, and had sailed from New Zealand to visit several sites.
