ROME — The Vatican tribunal hearing a landmark fraud case agreed Wednesday that the 10 defendants were deprived of their rights and ordered prosecutors to hand over key pieces of evidence and essentially start their investigation over for some of them.

Tribunal President Giuseppe Pignatone said there had been “lamentable violations” by the pope’s prosecutors in failing to give the suspects the right to respond to all accusations against them during the preliminary phase of the investigation.

Pignatone also repeated his July 29 order for prosecutors to hand over the videotaped recordings of a key suspect-turned-star witness whose testimony formed the basis for several of the charges in the indictment. He rejected arguments that the witness’s privacy would be compromised if they provided the recordings.

The trial concerns the Holy See’s 2013 investment in a London real estate venture that lost the Vatican tens of millions of euros, much of it donations from the faithful that were spent on fees to Italian brokers.

Prosecutors have accused the brokers of defrauding the Holy See, and several Vatican officials of abuse of office, corruption and other charges.

Defense lawyers had argued that procedural errors throughout the investigation were so harmful to the defendants that the charges should be thrown out entirely.

The three-judge tribunal declined to issue a blanket voiding of the indictment for all 10 suspects. But in a decision read aloud in court Wednesday, the tribunal said four people had to be interrogated on all charges, and identified certain charges to which the others must be given the chance to respond.

Defense attorneys said they were pleased with the outcome.