Israel's ground-breaking surveillance technology was once feted as a prized export bolstering diplomatic ties abroad, but reports the secret spyware was also turned on citizens at home has trigged domestic outrage.
Bombshell allegations in Israeli media centre on the controversial Pegasus malware made by the Israeli firm NSO, which can turn a phone into a pocket spying device.
Last year, a sweeping investigation by an international consortium of journalists revealed the extent of Pegasus's use worldwide.
Now reports allege the spyware was also used domestically, targeting dozens of Israelis who were not suspected of criminal activity and without a judge authorising the surveillance.
According to Israeli business daily Calcalist, a list of 26 targets includes ex-advisors of former prime minister Benjamin Netanyahu, as well as his son Avner, senior leaders of government ministries, protest leaders and others.
Prime Minister Naftali Bennett has vowed action, saying the reported conduct was "unacceptable in a democracy".
On Tuesday, he called for a preliminary probe of the 26 named in Calcalist and said a more thorough investigation would be set up within days.
Calls by top officials have mounted for a state commission of inquiry, Israel's highest-level probe.
Pegasus allows users to invisibly infiltrate a mobile phone, sucking up a person's contacts, conversations, photographs and data, and enabling remote activation of a phone's camera and microphone.
Writing in the Yediot Aharonot daily, Nadav Eyal noted that Israel developed cyber surveillance tools "mainly to track Palestinian terror organisations".
Gradually the technology use expanded, first as Israel followed non-violent Palestinian activists, and later when the spyware was privatised and sold abroad as "political gifts by the government of Netanyahu", Eyal wrote.
Last year's global investigation - focused on the spyware's deployment in more than 50 countries - found among a list of thousands of potential surveillance targets 180 journalists, 600 politicians, 85 human rights activists, and 65 business leaders around the world.
Eitay Mack, a lawyer suing NSO on behalf of Hungarian journalists who were allegedly targeted, told AFP that Pegasus exports "were out of control".
Israel's defence ministry has to approve all defence industry exports, and the country has faced widespread criticism over NSO's sales to governments with poor human rights records.
NSO says its software was intended for fighting crime and terrorism.
Israel had initially defended its export control procedures but, as criticism mounted, the defence establishment announced a review.
Mack argued that as Israel continued to sell the invasive technology to governments across the world, "there was an internal normalisation within the Israeli government to use it" against its own citizens.
'Like a boomerang'
Among those voicing outrage is Netanyahu, now the parliament's opposition leader.
"Police illegally spied with the most aggressive tools in the world on countless citizens - journalists, social activists from right and left, mayors, businesspeople, politicians, their families," Netanyahu told lawmakers on Monday.
"They followed them, listened to them, entered their deepest secrets, and who knows what forbidden use they made of this spying."
Mack said it was "embarrassing" that Netanyahu-led governments enthusiastically sold the programme to "authoritarian" leaders around the world - but that the spying technology ended up being used against his inner circle.
Multiple witnesses in an ongoing corruption case against Netanyahu were also reportedly spied on, according to the Calcalist report.
The motivation for the reported spying on Netanyahu's son Avner, his former advisors and witnesses at his trial is not clear.
But his lawyers have demanded the case -- in which he is accused of bribery, fraud and breach of trust, allegations he denies -- be put on hold while the spyware claims are probed.
The Jerusalem District Court cancelled hearings scheduled for this week, and instructed prosecutors to answer questions from the former premier's lawyers about the extent of the espionage.
Mack argued Pegasus has come back on Netanyahu "like a boomerang".
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