VATICAN CITY (RNS) — Cardinal Angelo Becciu, who was convicted of fraud and embezzlement and sentenced to 5 ½ years in prison by a Vatican court, appealed his case on Monday and Tuesday (Sept. 22-23).

Becciu, formerly the third-highest-ranking prelate at the Vatican, and eight others were found guilty in a 2023 Vatican megatrial revolving around a controversial purchase of real estate in London using Catholic funds that were partially destined for the pope’s charitable causes. As they brought their case before the six judges of the Vatican Court of Appeal this week, the defense moved to recuse the Vatican prosecutor Alessandro Diddi, accusing him of judicial meddling during the original trial.

On Monday, the Vatican appeals court accepted the motion of admissibility of the recusal. Diddi will have three days to respond, or his case will be brought before the Vatican’s highest court of appeal, the Court of Cassation, composed of four cardinal members. Until then, Diddi said he will not attend the hearings.

“Finally, I have the possibility to defend myself from a series of insinuations,” Diddi told the court. “I want to take advantage of the three-day period to express my considerations calmly, in order to dissolve the doubts that in these months have been raised about the conduct of the investigation.”

More than 3,200 pages of WhatsApp messages between Francesca Chaouqui and Genevieve Ciferri suggest the two conspired to coach Monsignor Alberto Perlasca, the prosecution’s star witness, on his testimony. Chaouqui, a former member of the Vatican’s commission for economic reform, was previously accused in 2015 of leaking sensitive documents.

Perlasca, who had been a longtime aid for Becciu when the cardinal was head of the Vatican Secretariat of State’s administrative office, offered key testimony during the trial. According to the defendants, Diddi operated behind the scenes through Chaouqui and Ciferri to manipulate Perlasca. According to the defendants, the messages raise doubt about Diddi’s impartiality.

“With his intervention this morning, Professor Diddi has personalized the Becciu trial, transforming it into a matter that involves his office and perhaps the entire judicial institution,” said Cataldo Intrieri, the lawyer of the financier Raffaele Mincione, after Monday’s hearing. “Does he not realize he risks turning the Becciu trial into the ‘Diddi affair’?” he added.

The “Diddi affair” also risks becoming a catalyst for the broader accusations that have been made against the Vatican judicial system, with defendants criticizing its lack of transparency, its dated legal norms and the ways it is subject to the pope. During the investigations into the controversial London property deal, Pope Francis intervened at least four times with decrees to strengthen the power of the prosecutors and reform financial oversight.

If the Court of Cassation upholds the recusal it would be a significant blow to the prosecution and it would also call into question the validity of the initial trial. Diddi has been involved with the Becciu trial for years and is familiar with the history and legalities of the case. In a 2021 decree, Pope Francis updated the code of criminal procedure to clarify that the office of the promoter of justice is present at all three levels of judgment, including appeal.

During the second day of trial, the court focused on procedural objections raised by the defense and prosecution. Discussions centered on the Vatican’s 1913 Code of Criminal Procedure, along with email and paper findings. The defense also argued that the prosecutor’s office mishandled the deadlines and format of its own appeal, meaning that if the judges agree, the prosecutor’s appeal might be considered invalid. This would make the appeal trial much shorter, focusing solely on the convictions.

The next trial date has been scheduled for Thursday.