SYDNEY : Wildlife officials Monday said rescue efforts had saved 11 whales from a mass stranding on an Australian beach, with the animals now swimming freely in deep water and unlikely to return to land.

Some 64 pilot whales, many of them mothers and calves, were found stranded on Anthonys Beach on the southern Australian island of Tasmania on Saturday.

Fifty-three of the animals died but rescuers worked throughout the weekend to save the rest, eventually hauling 11 of them on to specially-modified vehicles and driving them to a nearby beach for release into the sea.

Tasmania's Parks and Wildlife Service said satellite tracking devices which had been fitted to five of the rescued whales indicated that the animals were now swimming freely in deep water in Bass Strait.

"While this is good news, we will monitor the wider area with an aircraft," spokesman Chris Arthur said in a statement.

Wildlife officials said they were delighted the 11 rescued whales had regrouped in the water and said it was likely that they would also join up with humpback whales in the area.

"Not only have they survived being put back in the water after their traumatic ordeal but they've also found each other and are travelling with each other," the Department of Primary Industries and Water's David Pemberton said.

He said the tracking devices had proven that the rescue efforts, which involved swooping huge nets around the beached animals and hauling them on to vehicles and then releasing them at another beach, had been successful.

"For the first time in Australia, we have now got data which tells us that they are doing okay -- it is fantastic and incredibly exciting," Pemberton told national news agency AAP.

"In Tasmania, we deal with most whale strandings reported in Australia and previously, rescue attempts have been something of a hope and a prayer.

"Now we know that the rescue efforts are well worth it -- we have the evidence that tells us so."

Whale strandings are not uncommon in Tasmania but why they occur remains a subject of scientific debate.

Officials said autopsies will be carried out on the dead whales, which measured up to three metres (10 feet) in length.

- AFP/vm