I tried Wikipedia, and it led to some interesting first-hand reports (http://www.warbirdforum.com/secret.htm) but I was hoping to find something a bit more substantial by a historian.

As background: I am a Malaysian, and I know there were British planes stationed here during the invasion of Malaya (until the Japanese invaded), and more so that the RAF operated from India and Ceylon during the later years of the war and operated Spitfires. There's just so little information about this that I could find here.