Pope Francis is currently under intense pressure to tackle thousands of reports of paedophilia within the Catholic Church that have surfaced around the world.
The Portuguese inquiry, commissioned by the Church in the staunchly Catholic country, published the results of its investigation after hearing from more than 500 victims.
In October, the team of six experts said it had recorded 424 legitimate accounts from presumed victims but warned that their testimony indicated the total number of victims was “much larger”.
“This testimony allows us to establish a much larger network of victims, at least 4,815,” child psychiatrist Pedro Strecht told a press conference in Lisbon.
The accounts revealed “serious situations which persisted for decades … and in some cases reached epidemic proportions”, it said at the time.