I…saw him several times in Tegel prison, until our contact was finally broken off as a result of my own arrest in October 1944. The Gestapo explored my relation with the Schleicher family (Eberhard married Renate Schleicher, the daughter of Bonhoeffer’s sister, Ursula), but neglected to investigate my ties to Dietrich Bonhoeffer. Thus I survived. 

~ Eberhard Bethge, Dietrich Bonhoeffer: A Biography (Revised Edition); Preface to the First English Edition (1970), xv.