Now tests at Oxford Brookes University on hairs said to be from a Yeti in India have failed to link the strands with any known species.
Ape expert Ian Redmond, who is leading the research, said: "The hairs are the most positive evidence yet that a Yeti might possibly exist.
"It may be that the region this animal is inhabiting is remote enough for it to remain undiscovered so far."
The two hairs - 33mm and 44mm long - were found in a jungle in the mountains of north-east India five years ago.
A forester claimed to seen a Yeti, known locally as mande barung or "forest man", two days in a row breaking branches off trees and eating their sap.
The Yeti was dubbed the Abominable Snowman in 1921 after an Everest expedition found large footprints at 21,000ft.
Climber Sir Edmund Hillary also found large footprints on Everest in 1953.
And in December last year, an American TV presenter reported 33cm-long footprints in the Everest region of Nepal.
The scientists are using high-powered microscopes to analyse the samples.
The hairs will then be sent to labs in Oxford and Cardiff for DNA testing.
If DNA analysis cannot identify the creature, it should be able to establish what it is related to.
The scientific community has largely dismissed the possible existence of Yeti but it remains one of the most famous creatures of cryptozoology, the study of unconfirmed animals.
Mon Jul 28 2008 13:25:54 GMT+0100 (GMT Daylight Time)