Climbing inside the carcass of a whale was once thought to bring relief to rheumatism sufferers, an Australian National Maritime Museum exhibit shows.

Staying inside the whale for about 30 hours was believed to bring relief from aches and pains for up to 12 months.

A rheumatic patient would be lowered inside the carcass of a recently-slaughtered whale "leaving just his or her head poking out ."

One claim for the origins of the practice, which dates back to the late 19th Century, is that a drunk man plunged into the carcass of a whale and emerged hours later apparently free of his rheumatism.