My recollection is that Catholic clerical abuse scandals hit the global consciousness big-time only in the late 1980s. Before that, it was mostly just confined to hushed innuendo in Catholic circles and snide jokes in non-Catholic ones.
The earliest cases I can recall in Canada were the Christian Brothers cases in Newfoundland, which hit the news in 1989 or so. Those were the first significant cases I remember in Canada, but I seem to recall that they might have been following on the heels of revelations elsewhere.
I'm not exactly sure what made people at that time suddenly sit up and take notice of things that had been going on under everyone's collective nose for decades if not centuries. Possibly the weakened authority of the Catholic Church in traditional Catholic communities had something to do with it.
Whatever the social circumstances were that led to greater disclosure, I guess a good route for your scenario would be to get those circumstances somehow duplicated in Ireland. Though I notice that your OP calls for a BRITISH newspaper to expose the crimes. Is this because you regard Ireland at the time as being internally incapable of finding out on its own?