Fascinating. Never heard of this one before. According to the natives, during WWII the Japanese supposedly found multiple sarcophagi lined with platinum, containing longer-than-usual bodies there, but Japan claims no knowledge of this today.
Probably because the story is a total fabrication. Platinum is not found in very many places in quantity (common in some meteorites), and none of those places are in the Pacific, or anywhere near Micronesia.
In the WWII era there were cargo cults in the region that believed some pretty strange things.