Ratzinger apologized for his actions and said he was relieved in 1980 when Germany banned corporal punishment in schools, The Times of London reported. He headed the Regensburger Domspatzen from the early 1960s to 1994.
The allegations of abuse of children in Germany have raised questions about Pope Benedict, who spent his early career as a professor of theology and bishop of Munich before becoming a top Vatican official in 1982.
"I myself handed out slaps repeatedly, although I always had a bad conscience about it," Ratzinger told the Passauer Neue Presse, a Catholic newspaper.
Ratzinger denied knowing boys were sexually abused. He said the choirmaster was "a king without a kingdom" in the school hierarchy and that the tone was set by the "very violent" headmaster who served from 1953 to 1992.
One former student, Franz Wittenbrink, now a composer, has described the headmaster as a sexual sadist. Wittenbrink said the headmaster, identified only as Johann M., would often order two or three boys into his office during the evening.