As I think I answered in a previous question, I was made aware of these two cases in a general way near the end of 2009. The service had been working on these for some time; I don't know quite how long. As I said earlier, I was sufficiently concerned about the matter that I raised them with the national security adviser in early 2010, although largely with the view of finding out what protocol would apply should it be decided that we needed to contact anyone outside of the federal government.
On July 5th, 2010. See this statement in context.