Bureaucratic "impediments" with India have disrupted efforts by the US Government to recover the remains of several hundred of their military aviators who crashed and died in the country's remote northeast region during World War II.
Some 500-600 United States warplanes crashed in the 1940s in hazardous missions over the Himalayas against the Japanese.
They came down in the thickly-forested Arunachal Pradesh state bordering Tibet and Burma - then known as the North East Frontier Agency - while operating a perilous air-lift to sustain Allied troops and China's Kuomintang army fighting the advancing Japanese.
The route was known as "the hump" because of the 4500m high ridges which the rudimentary aircraft had to navigate with little or no instrumentation in winds of over 160km/h. But it became known as the "aluminum trail" due to the number of wrecks that marked its path.
Over decades, families of the dead pilots and teams from the US Joint POW/MIA Accounting Command (JPAC) in Honolulu identified several crash sites.
They estimated the remains of 400-500 US pilots lay scattered across the mountainous region and wanted them brought home for a proper burial.
The JPAC executes investigations and recovery missions for missing American military personnel. Some of the crash sites, however, lie across the border in Burma and were not accessible to US reconnaissance teams.
But recent requests by the US embassy in New Delhi to the Indian Government to dispatch teams to retrieve these pilots' remains had, for "bureaucratic" reasons, not been sanctioned.
India's Defence Ministry declined to comment as did the Foreign Office spokesman.
JPAC spokesman Tara Rigler, through the US embassy in New Delhi, stated they were working closely with the Indian Government to "resume recovery remains missions in northeast India as soon as possible" but did not elaborate.
Arunachal Pradesh, like some other adjoining north-eastern states - many of them wracked with insurgencies - remains closed to foreigners, particularly US nationals with all outsiders requiring special Protected Area Permits that are not easy to obtain.
This access denial to foreigners stems from the federal Government's belief the many armed separatist movements were instigated by some Christian missionaries, descendants of those who came to the region in the 19th century and were proscribed in the 1960s.
Arunachal is also claimed by the Chinese as part of southern Tibet in a long-running territorial dispute with India and officials hinted New Delhi's sensitivity to Beijing's concerns could also be the reason for not permitting US JPAC team's entry to the region.