After World War II, he was arrested in July 1945 in Râmnicu Vâlcea by the Siguranța secret police and detained for several days. Once the communist regime was installed in Romania, Boca was persecuted by the authorities and the regime's secret police, the Securitate. He was arrested and imprisoned several times for allegedly helping the Romanian anti-communist resistance movement. As reported by Ion Gavrilă Ogoranu in a 1999 interview, General Dumitru Coroamă, a resistance leader who was based in Sibiu, travelled in the fall of 1947 to Sâmbăta de Sus Monastery and met Boca, with whom he planned various anti-communist activities. In June 1948 Boca was arrested and detained at the Securitate facility in Făgăraș. After being released in November, Boca was removed from Brâncoveanu Monastery to Prislop Monastery and thence to Sinaia Monastery.