The FBI has revealed details of its 1970s investigation into what was known as "Bigfoot".
More than 20 documents from the investigation have been released to the public via the FBI's Records Vault, showing how it was urged to pursue what researcher Peter Byrne claimed was evidence of the hairy creature, which was also known as "Sasquatch".
Mr Byrne was director of the Bigfoot Information Centre and Exhibition based in Oregon, which he explains in the documents as "an institution that conducts research on and into the Bigfoot phenomenon of the Pacific Northwest of the US" and "associated with the Academy of Applied Science of Boston, Massachusetts". It consisted of 300 members and one staff member.
He described the group's research as "serious" and after asking the FBI to "set the record straight" about supposed earlier analysis of hair samples, he asks for a study of 15 hairs attached to some skin which his group has been unable to identify. He adds that it is the first sample it has obtained in six years "which we feel may be of importance".
The request for examination of the hair samples was granted by the FBI "in interest of research and scientific inquiry", according to a United States Government memorandum dated December 13, 1976.
The examination included a study of "morphological characteristics such as root structure, medullary structure and cuticle thickness in addition to scale casts". The hairs were also compared with those of known origin.
Mr Byrne's reaction to the results was not known as he was said to be away in Nepal for a number of months when the investigation was concluded.
But the FBI were clear in their findings: "It was concluded as a result of these examinations that the hairs are of deer family origin," Jay Cochran Jr, assistant director FBI, scientific and technical services division, revealed on February 24, 1977.
Now 93, Mr Byrne told CNBC on Wednesday that he is still actively searching for proof of Bigfoot, although it's more of a hobby for him now.
“I’d love to see one," he said.