Google “Operation Gladio”.
In 2004 the German author Norbert Juretzko published a book about his work at the BND. He went into details about recruiting partisans for the German stay-behind network. He was sacked from BND following a secret trial against him, because the BND could not find out the real name of his Russian source "Rübezahl" whom he had recruited. A man with the name he put on file was arrested by the KGB following treason in the BND, but was obviously innocent, his name having been chosen at random from the public phone book by Juretzko.[29] According to Juretzko, the BND built up its branch of Gladio, but discovered after the fall of the German Democratic Republic that it was fully known to the Stasi early on.