VATICAN CITY -- The Vatican said Wednesday it had placed two Italian journalists under investigation in its probe over leaked documents that revealed waste, greed and mismanagement at the highest levels of the Catholic Church hierarchy.

Journalists Gianluigi Nuzzi and Emiliano Fittipaldi wrote two bombshell books detailing the uphill battle Pope Francis is facing in reforming the Vatican bureaucracy. Their books, released last week, were based on leaked documents from a reform commission Francis named to get a handle on the Vatican's finances and propose reforms so that more money could go to charity.

Already, two members of the commission who had access to the documents have been arrested by Vatican police.

Vatican spokesman the Rev. Federico Lombardi said Wednesday that Nuzzi and Fittipaldi had been placed under investigation by Vatican magistrates for their alleged role in dealing with the leaked documents. He said other officials were being looked at for having possibly co-operated in the scandal.

Reached in Berlin, Nuzzi said he knew nothing of the investigation. Fittipaldi was quoted by his L'Espresso magazine as saying the investigation was the price he has to pay for doing his job.

In the Italian and Vatican legal systems, people are frequently placed under investigation without charges ever being filed as part of the information-gathering process by investigative magistrates. It wasn't immediately clear that the Vatican would have jurisdiction over the two journalists if they saw or obtained the documents outside Vatican territory.

After Nuzzi published a bombshell book in 2012 based on documents given to him by Pope Benedict XVI's butler, the Vatican criminalized the leaking of documents.

The new books were based on internal reports that revealed millions of euros in lost rental income from the Vatican's vast real estate holdings, millions in missing inventory from the Vatican's tax-free stores, the exorbitant costs for getting a saint made as well as the greed of monsignors and cardinals who lusted after huge apartments.

Singled out for particular scorn has been Cardinal Tarcisio Bertone, the secretary of state under Pope Benedict XVI who has long been blamed for many of the administrative, financial and communications problems of Benedict's troubled papacy. Bertone was the main target of the leaked documents in Nuzzi's 2012 book on Vatican waste and mismanagement, which some say helped prompt Benedict to resign.

Fittipaldi's book "Avarice" picked up where Nuzzi left off, revealing that the foundation of Italy's pre-eminent children's hospital, the Holy See-owned Bambino Gesu, paid 200,000 euros ($215,000) to renovate Bertone's Vatican apartment after he retired. Bertone has insisted he paid 300,000 euros for the fix-up out of his own pocket.

On Wednesday, Bertone confirmed that he had recently learned that the foundation had also paid the bill but that he had never told it to do so. In a letter to the newsweekly of his former Genoa diocese, Bertone said he had asked his lawyer to investigate and that he would take action if any "fraudulent action had been conducted in my name."

The books have spawned a week of headlines in Italian newspapers, prompting the Vatican on Wednesday to come out in force to dispute the reports and warn that it would take legal steps to protect its name.

The Vatican's Congregation for the Propagation of the Faith, for example, denounced as "unacceptable" reports that it had rented out some of its prime real estate at below-market rates, saying all of its properties are rented at market prices with a few exceptions for indigent situations.

The congregation, also known as "Propaganda Fide," uses its rental proceeds to fund the church's activities in the developing world, as well as the Pontifical Urbaniana University which trains priests and nuns from poor countries. It insisted that it was fully on board with Francis' reform agenda amid previous reports that it had resisted turning over financial information to the reform commission and the Vatican's new Secretariat for the Economy.

Pope Francis' top deputy, Cardinal Pietro Parolin, said Wednesday the reports have bordered on "hysteria" and were simply "attacks on the church."

He acknowledged, however, that Francis' reform agenda has run into "resistance."

"Changing things is always difficult because we're always tempted to continue in the daily ho-hum way we do things," Parolin told Vatican Radio. But he said the key was to "transform what can be normal resistance in the face of change into tools for reform."