A suspected leak of classified Gaza documents involving an aide to Prime Minister Benjamin Netanyahu has jolted Israeli politics and outraged the families of hostages held by Hamas who have been pushing for a deal to get their loved ones home.
Details of the case have trickled out slowly because of a gag order.
But a magistrate's ruling partly lifting the order has provided an initial glimpse of the case that the court said had compromised security sources and may have harmed Israel's efforts to release the hostages.
"Classified and sensitive intelligence information was taken from IDF (Israel Defence Forces) systems and taken out illegally," a ruling by the Rishon Le-Zion Magistrates' Court said on Sunday, which may have caused "serious damage to the state's security and posed a risk to information sources".
In that, the court said, the leak could have hurt efforts to release the hostages.
Netanyahu has denied any wrongdoing by his office staffers and said in a statement on Saturday that he was only made aware of the leaked document by the media.
The four suspects - one a spokesman from Netanyahu's circle and three of them members of the security establishment - could not be reached for comment.
Details from the document in question were published by the German Bild newspaper on September 6, according to Israeli newspaper Haaretz, one of the media outlets that had appealed the court to lift the gag order.
The article, labelled as an exclusive, purportedly outlined the negotiation strategy of Hamas.
Around that time, the United States, Qatar and Egypt were mediating ceasefire talks between Israel and Hamas, that were to include a deal to release hostages held in Gaza.
But the talks faltered with Israel and Hamas trading blame for the deadlock. The article in question largely corresponded with Netanyahu's allegations against Hamas over the impasse.
On Saturday, some of the families joined the Israeli journalists' appeal to lift the gag order.
"These people have been living on a rollercoaster of rumours and half truths," said their lawyer, Dana Pugach.
"For the last year they have been waiting to hear any intelligence or any information about negotiations for the release of those hostages. If some of that information had been stolen from army sources then we think that the families have the right to learn about any relevant detail," she added.
In another session on Sunday about the investigation by the Shin Bet domestic security service, police and the military, the court ordered one suspect be released, while keeping others in remand, according to Haaretz.
Asked about the investigation, Bild said that it does not comment on its sources. "The authenticity of the document known to us was confirmed by the IDF (Israel Defence Forces) immediately after publication," it said.