They face up to eight years in prison if convicted of charges of violating Vatican law.

Two Italian journalists, who wrote books detailing Vatican mismanagement, go on trial on Tuesday in a Vatican courtroom along with three people accused of leaking them the information in a case that has drawn scorn from media watchdogs around the world.

The Committee to Protect Journalists, Reporters Without Borders and the OSCE, among others, have all called on the Vatican to drop the charges against Gianluigi Nuzzi and Emiliano Fittipaldi. The two reporters face up to eight years in prison if convicted of charges that they violated Vatican law by publishing news based on confidential Holy See documents.

“Process Kafka-esque”

In interviews Monday, Mr. Nuzzi and Mr. Fittipaldi both called the process “Kafka-esque.” With hours to go before the start of trial, neither they nor their lawyers had seen the court file detailing the accusations against them. Mr. Nuzzi only spoke for the first time with his Vatican court-appointed lawyer Monday morning. They were indicted on Friday.

Even though they technically risk arrest by stepping on Vatican soil on Tuesday, both said they planned to attend the trial if only to report to the world what transpired. The Vatican is a sovereign state, and by entering Vatican territory, Mr. Nuzzi and Mr. Fittipaldi could well be detained by Vatican gendarmes given the grave accusations against them. But neither expected the Vatican would take that route, given the diplomatic incident it would set off with Italy.

Trial against press freedom

“This is a trial against freedom of the press,” Mr. Fittipaldi said in an interview at his offices in the headquarters of Rome’s La Repubblica newspaper. “In no other part of the world, at least in the part of the world that considers itself democratic, is there a crime of a scoop, a crime of publishing news.”

Since Mr. Nuzzi and Mr. Fittipaldi are Italian citizens, any sentence would involve an extradition request. Both journalists said they believed no Italian judge would extradite them, given freedom of the press is guaranteed by the Italian Constitution and that Italy would be loath to extradite two of its citizens to a State that doesn’t respect the same fundamental right as free expression.

Greed of cardinals, bishops

Mr. Fittipaldi’s book Avarice, and Nuzzi’s book Merchants in the Temple, both published earlier this month, detail waste and mismanagement in the Vatican administration, the greed of some cardinals and bishops and the resistance Pope Francis is facing in trying to clean it up.

Both books were largely based on documents produced by a special reform commission Pope Francis named to get a handle on the Vatican’s financial holdings and propose reforms so that more money could be given to the poor. The three other people on trial were affiliated with the commission -- Monsignor Angelo Lucio Vallejo Balda was its No. 2, Francesca Chaouqui was a member and outside public relations expert, and Nicola Maio was Mr. Balda’s assistant.

Criminal organization charge

All three are accused of forming a criminal organization and of procuring and leaking confidential documents. Mr. Nuzzi and Mr. Fittipaldi, meanwhile, are accused of publishing those documents and of “soliciting and exercising pressure, above all on Vallejo Balda, to obtain the documents and other reserved news,” according to prosecutors.

The journalists deny the pressure accusation but acknowledge that they, like all journalists, obtained information and published it. Ms. Chaouqui has denied wrongdoing and was allowed to escape detention after she cooperated with investigators. Mr. Balda, who is in Vatican detention, and Ms. Maio, haven’t responded publicly to the accusations.

Criminalised in 2013

The Vatican in 2013 criminalised the leaking of confidential information and publishing news from that information after Mr. Nuzzi wrote a blockbuster book detailing the corruption, intrigue and petty turf battles that bedevil parts of the Vatican. Some say the scandal had a role in Pope Benedict XVI’s decision to resign.

The trial bears some resemblance to that of Pope Benedict’s butler, Paolo Gabriele, who was convicted by the same Vatican tribunal of stealing the Pope’s private papers and leaking them to Mr. Nuzzi. He was sentenced to 18 months in prison but Pope Benedict eventually pardoned him. Like that trial, this one will be open to a small group of journalists acting as “pool” reporters for the proceedings.

In a statement on Monday, the Committee to Protect Journalists called on the Vatican to drop the charges. “Journalists should be allowed to carry out their role as watchdog and investigate alleged wrongdoing without fear of repercussions,” said the Nina Ognianova of the CPJ’s Europe and Central Asia program.

The Organization for Security and Cooperation in Europe’s media freedom representative, Dunja Mijatovic, echoed the call, saying “journalists must be allowed to report on issues of public interest and to protect their confidential sources.”