Edward Bancroft (January 9, 1744 - September 8, 1820) was an American physician and double agent in the American Revolution. Born in Westfield, Massachusetts, he worked as a spy for Benjamin Franklin when he was secretary to the American Commission in Paris. However, he was also a spy for the British who would report on American and French dealings. Wikipedia
The spy, Dr. Edward Bancroft, was never discovered until seventy years after his death when the British government provided access to its diplomatic archives. www.fas.org/irp/ops/ci/docs/ci1/ch1c.htm
The definitive Wikipedia entry for Edward Bancroft. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Edward_Bancroft