SANTIAGO, Chile — Pope Francis has defrocked a once-prominent priest whose case has been at the center of public outrage about clerical sexual abuse and its concealment in Chile — a rare move that Vatican officials said showed his determination to tackle a scandal that has roiled the Catholic Church here and around the world.

The priest, the Rev. Fernando Karadima, was found guilty of sexual offenses by the Vatican as long ago as 2011. But his case has proved particularly toxic for Francis, who long defended a bishop accused of covering it up, Juan Barros, including during a visit to Chile in January.

A month later, following a storm of protest, Francis sent sex crimes investigators to the country, beginning an about-face that was to result in all 34 of the Roman Catholic bishops in Chile offering their resignations.

“It is one more step in Pope Francis’ determined stance against abuse,” a Vatican spokesman, Greg Burke, said of the decision to defrock, which was announced on Friday. We were before a very serious case of putrefaction that had to be pulled out from its roots.”