Richard Paterson, master blender at Whyte and Mackay, whose company supplied the Mackinlay's whisky for Shackleton, described the find as "a gift from the heavens" for whisky lovers.

"If the contents can be confirmed, safely extracted and analysed, the original blend may be able to be replicated," he said.

"Given the original recipe no longer exists this may open a door into history."

Fastier said the Trust would determine in the coming weeks how best to handle the "delicate conservation task".

Shackleton's expedition ran short of supplies on their long trek to the South Pole from Cape Royds in 1907-1909 and they eventually fell about 100 miles (160 kilometres) short of their goal.

No lives were lost, vindicating Shackleton's decision to turn back from the pole, first reached in 1911 by Norwegian explorer Roald Amundsen.

Shackleton's expedition sailed from Cape Royds hurriedly in 1909 as winter ice began forming in the sea, forcing them to leave some equipment and supplies -- including the whisky -- behind.

The excavation of the whisky follows the discovery last month of two blocks of butter in an Antarctic hut used by British explorer Robert Falcon Scott on his doomed 1910-12 expedition.

The butter had been stored in stables attached to the expedition hut at Cape Evans in Antarctica.