A US television show with four Christian ministers interviewing Rupanuga Prabhu, one of the first disciples of Srila Prabhuapda who joined ISKCON in 1966. They are trying to understand what is this Krishna Consciousness movement. This is from about 1980.
From 1972 US Television show Challenge My Sermon. Umapati das presents a sermon on Krishna consciousness and it is challenged by a pannel of Christians. Umapati das was one of the first disciples of His Divine Grace A.C. Bhaktivedanta Swami Prabhupada, he joined ISKCON in 1966.