Birendra Nath Mazumdar M.D. (1914 or 1915 – December 1997) was an Indian medical officer in the Royal Army Medical Corps serving in France in 1940. At the time, he was the only Indian officer in the British Army, and after his capture by the Germans, he was the only Indian POW to be held in Oflag IV-C, Colditz. After forcing a transfer to an all-Indian POW camp in France, he escaped to Switzerland in 1943.
This is one of only 50 covers signed by Mazumdar and is extremely rare. He is one of only 30/31 Colditz inmates to make it back home  during the war. The cover is in superb condition. The only other examples seen on the internet are up for sale at £250.