A mother whose son is being held hostage by Hamas in Gaza has accused Israel’s government of “a cynical deception operation that is taken from dark regimes”, after it emerged a government spokesperson had been arrested for allegedly leaking documents that may have undermined a ceasefire and hostage release deal.

It came after a court in Rishon LeZion said Eli Feldstein and three others were under investigation for feeding stories to European newspapers.

Israel Defense Forces (IDF) Radio also reported a fifth arrest in connection with the probe, said to be a major in the military’s intelligence branch information security department, tasked with preventing and investigating leaks. The Haaretz newspaper said all unnamed suspects were from this unit.

Prime Minister Benjamin Netanyahu has denied wrongdoing by his staff, but opposition figures and hostages’ families have accused his government of sabotaging negotiations.

The stories, given to Britain’s Jewish Chronicle and Germany’s tabloid Bild, were based on partial or false information and came at a crucial time for hostage negotiations.

Speaking at a protest in Tel Aviv, Einav Zangauker, whose son Matan has been held by Hamas for over a year, said the stories “supported Netanyahu’s propaganda lies to torpedo the deal”.

The documents claimed Hamas was planning to smuggle Israeli hostages to Egypt – intent on scuppering any proposed ceasefire deal.

Some commentators say the revelations were politically useful for Netanyahu’s hardline position on the talks, which have made almost no progress.

Over 100 hostages out of 251 taken by Hamas on 7 October 2023 remain unaccounted for.

After the stories were published in September, the IDF launched an inquiry to discover the source of the leaks.

This eventually led to the arrest of Eli Feldstein, along with the three others, whose identities have not been revealed.

Mr Feldstein had been working as a government spokesperson and was often seen accompanying the prime minister on visits. He had previously worked for the far-right Minister of National Security, Itamar Ben-Gvir, and before that he served as an IDF spokesperson.

Following news of his arrest, two leading opposition politicians held a news conference.

Benny Gantz, who until recently was in Netanyahu’s war cabinet, said that if sensitive security information was used for a “political survival campaign”, it would not only be a criminal offence, but “a crime against the nation”.

Speaking at the same event, the leader of the opposition, Yair Lapid, said that if the prime minister knew about the leaks, “he is complicit in one of the most serious security offences” and that if he didn’t know, he is not fit for office.

The revelations also led to strong criticism from the families of the hostages, who have become increasingly frustrated with the government’s failure to secure the release of their loved ones.

They said it implied an active campaign to discredit them, calling it “a moral low that has no depth. This is a fatal injury to the remnants of trust between the government and its citizens.”

The documents were published in European newspapers, allegedly to circumvent military censorship laws in Israel.

The Jewish Chronicle (JC) was engulfed in a scandal after it emerged it had published stories based on a single anonymous source. The freelance writer behind the pieces was fired, with the articles eventually being taken down.

The articles claimed that the late Hamas leader Yahya Sinwar – who was killed by Israeli troops in southern Gaza last month – was surrounded by a ring of about 20 hostages, and that plans had been discovered to smuggle both Sinwar and the captives into Egypt. Leading Israeli security journalists questioned the veracity of the reports.

A number of high-profile writers resigned from the paper, accusing it of lacking journalistic standards.

Jonathan Freedland, Hadley Freeman and David Aaronovitch announced they were quitting their columns over what Freedland described as a “great disgrace” at the world’s oldest Jewish newspaper.

At the time, the JC said it conducted a “thorough investigation” into one of its freelance journalists, Elon Perry, “after allegations were made about aspects of his record”.

It said it was “not satisfied” with some of the claims made by the writer, and therefore had deleted his articles and ended its association with him.

Elon Perry told BBC News the JC “made a huge mistake with its statement”. He said he could not reveal his source to JC editors and described a “witch-hunt against me caused by jealousy”.

The Bild articles, meanwhile, were based on a different set of intelligence documents. While they were found to be authentic, leading security journalist Ronan Bergman found their significance had been greatly exaggerated.

It was the publication of this story that triggered the investigation by the IDF and security services, ultimately leading to the arrests.

Despite the fierce criticism he is facing, few people here think the scandal will prove fatal for Netanyahu’s premiership. He is already facing multiple court cases on charges of bribery, fraud and breach of trust, which he denies, yet remains in power, propped up by a coalition of far-right and religious parties.

“It’s not like there’s a charge where you can say, ‘Well, they haven’t thrown this yet against the prime minister, this is going to bring him down,’” says Anshel Pfeffer, a leading commentator for the Haaretz newspaper.

He told me there was no sign of the government collapsing. “Their line has been that he is the victim of a cabal of lawyers and journalists, and now they’re also adding in the security establishment, who they say are out to get him.”

Netanyahu has sought to distance himself from the allegations, saying the arrested spokesperson had never had access to classified information.

Despite that, this is a growing scandal that has further damaged the already frayed relationship between the government and the hostage families.