Controversy erupted Wednesday after Poland's Roman Catholic Church silenced a priest investigating clergy who allegedly spied for the communist-era secret service. Catholic priest Tadeusz Isakowicz-Zaleski was ordered by decree to keep quiet about information he has gathered regarding Roman Catholic clergy who are alleged to have acted as agents for communist-era intelligence services prior to 1989.

"This is very painful," Isakowicz-Zaleski told Poland's commercial Tok Radio Wednesday. "I want to know what happened that things have changed so suddenly over the last few days - even every criminal has a right to know why they have been punished," he said.

The decree issued late Tuesday by the Krakow diocese alleged Isakowicz-Zaleski "distorts the image of a priest by becoming an inquisitor and a merciless and ruthless accuser."

The Krakow diocese is headed by Cardinal Stanislaw Dziwisz, the former personal aid of the late Polish-born Pope John Paul II.