From the National Archives, here’s a 1959 letter from the US embassy in Kathmandu to the State Department, outlining the regulations to be adhered to for mountain climbing expeditions in search of the Yeti. Seems that while the Nepalese government was concerned for the safety of the legendary monster, they also sought to control the flow of any news and images (and actual specimens) confirming the creature’s existence:
Text from the letter:
There are, at present, three regulations applicable only to expeditions searching for the YETI in Nepal. These regulations are to be observed in addition to the 15 clauses as listed in Mountaineering and Scientific Expeditions in Nepal.
The three regulations are as follows:
Royalty of Rs. 5000/- Indian currency will have to be paid to His Majesty’s Government of Nepal for a permit to carry out an expedition in search of ‘Yeti’.
In case ‘Yeti’ is traced it can be photographed or caught alive but it must not be killed or shot at except in an emergency arising out of self defence. All photographs taken of the animal, the creature itself if captured alive or dead, must be surrendered to the Government of Nepal at the earliest time.
News and reports throwing light on the existence of the creature must be submitted to the Government of Nepal as soon as they are available and must not in any way be given out to the Press or Reporters for publicity without the permission of the Government of Nepal.