The remains measure 12 metres across Enlarge Image

The specimen was at first taken for a beached whale when it was washed up a week ago but experts who have seen it say it appears not to have a backbone.

"We'd never before seen such a strange specimen.

"We don't know if it might be a giant squid that is missing some of its parts or maybe it's a new species," Elsa Cabrera, a marine biologist and director of the Centre for Cetacean Conservation in Santiago, told Reuters news agency.

The mass is too big to be a whale skin and does not have the right texture or smell, she said.

Ms Cabrera said she was contacting Chilean and international organisations in the hope that they could help work out what the find was.

The Chilean navy first saw the remains along with another large mass which turned out to be a dead humpback whale.