I was very interested in the civilian interment camp in Los Banos, Laguna years ago. Had some research there but still lacking in data. There was a reliable story that during the near end of the war, the whole Japanese force in that camp left in trucks carrying lots of heavy powder drums and went up to Mt. Makiling. They returned after 2 or 3 days with less than 1 truck and no more powder drums.
In fact, it was one of the subject of quest of the CS (PSG) of the Marcos Era in 1981 led by one of the rolex boys (G Valle) but they failed to find it due to security reasons. Their source of info was the confessions made by the camp tyrant Warrant Officer Sadaaki Konishi. He was hanged anyway after the war.