Acutis, who is seen as the patron saint of the Internet, was a student from Lombardy who died from leukaemia at the age of 15 in 2006.
Assisi Bishop Domenico Sorrentino said Wednesday saying he had reported the case to the police.
Sorrentino has filed the complaint against a person or persons unknown over the alleged sale of Acutis’s relics.
He did not say what the relics were, but Perugia prosecutors are looking into the case.
Acutis’s body is preserved in the sanctuary of the Spogliazione at Assisi.
Acutis became a model of Christian life for many young believers and will be canonised during the Roman Catholic Jubilee in April after being beatified on October 10, 2020, in Assisi.
Last May, Pope Francis said Acutis had qualified to become a saint after another miracle was ratified for him.
The second miracle that has earned him his saint’s spurs was the miraculous healing of a young Costa Rican girl.
Acutis has been fast-tracked to sainthood and will be named a saint by Francis along with the Giuseppe Allamano, founder of the Consolata Missions.
ANSA