S'funny but there are very detailed records of every Spitfire ever built, and their service histories - including their ultimate disposal. We even know the names of the ships that transported them to ACSEA. These records show lots of Spitfires being turned over to both the Indian and Burmese air forces in 1947 upon indpendence. Many others are shown as being returned to UK.
So, why would we bury any of them? Its just another silly rumour. The Royal Air Force
destroys aircraft when its afraid of them falling into hostile hands and sells them to scrap merchants when it isn't. It doesn't waste time burying them in unmarked and unrecorded graves.