ROME -- Two senior ex-Catholic Church officials -- the president and treasurer of the Vatican's own prestigious pediatric hospital -- went on trial Tuesday to defend themselves against allegations that they diverted almost $500,000 in hospital donations to renovate a cardinal's retirement home.

As CBS News correspondent Seth Doane reports, the scandal sounds like something right out of a crime novel; It involves one of the Catholic Church's top cardinals, the renowned Bambino Gesu children's hospital and criminal charges of embezzlement for fancy renovations -- and it all comes as Pope Francis tries to tidy up the church's finances.

It's alleged that former hospital president Giuseppe Profiti and ex-treasurer Massimo Spina siphoned-off $485,000 dollars of money raised for the children's hospital to renovate the apartment of Cardinal Tarcisio Bertone.

Bertone had been the Vatican's number two authority; it's secretary of state, who serves directly under the pope himself.

Profiti argues the renovations were an investment, saying Cardinal Bertone was planning to let the hospital use his newly-renovated apartment to host fundraising events.

The cardinal has not been charged with any crime, and he insists he knew nothing about the money being diverted for the work on his Vatican-owned apartment.

Profiti and Spina face three to five years in prison and fines of at least $5,700 if they are found guilty.

"A scandal like this really plays to the stereotype of out-of-touch, arrogant cardinals growing fat on the wealth of the church," Notre Dame professor of theology Candida Moss tells CBS News.

"(Pope) Francis and the Vatican really need this trial, because their moral credibility and financial stability are at stake," Moss says. "If we don't see results in this trial -- if we don't see a prosecution -- people will wonder if Francis is really serious about financial reforms."

Thank you @bambinogesu for the heroic work you do. I ask that everyone keep these amazing children in your thoughts & prayers. pic.twitter.com/UfVAc9lXv2 — Melania Trump (@FLOTUS) May 24, 2017

Bambino Gesu is one of the leading pediatric centers in Europe. First Lady Melania Trump visited in May, and speaking to hospital staff in December, Pope Francis alluded to the trouble in its management by calling corruption "one of the worst cancers in a hospital."

Pope Francis is surrounded by children as he speaks with patients and caregivers from the Vatican's Bambino Gesu Pediatric Hospital, Dec. 15, 2016. AP

One Vatican-insider tells CBS News this tribunal is Pope Francis, "airing the church's dirty laundry in public... in a way we haven't seen before."

And Doane says it's worth noting that Cardinal Bertone's sprawling, 3,200-square-foot apartment stands out compared to its neighbour on the Vatican campus, the humble quarters where Pope Francis resides at the Santa Marta hotel.