Recent allegations that Pegasus spyware was used against three Polish government opponents are likely the "tip of the iceberg," said a cyber expert Wednesday who helped identify the phone taps.
Evidence of the hacking, which has become a major scandal in Poland, was reported by the Canada-based cyber-security watchdog Citizen Lab.
"We think this is just the tip of the iceberg and there'll be more discoveries to come," John Scott-Railton, a senior researcher with the group, told AFP.
"It's shocking and it looks very bad," he said. "Pegasus is a tool of dictators. Its use in these cases point to an authoritarian slide" in Poland.
Smartphones infected with Pegasus are essentially turned into pocket spying devices, allowing the user to read the target's messages, look through their photos, track their location, and even turn on their camera without their knowledge.
One of the victims, lawyer Roman Giertych, who is involved in several cases against the ruling Law and Justice (PiS) party, told Polish daily Gazeta Wyborcza that the government was using the spyware "to fight the democratic opposition."
Ewa Wrzosek, a prosecutor and opposition figure, also said the spyware had been used against her, adding that she was first alerted by Apple.
Scott-Railton confirmed Wednesday that Citizen Lab had also advised Senator Krzysztof Brejza of the opposition party Civic Platform, that his smartphone was repeatedly infected over a six-month period during the 2019 election.
"Their lives were under close monitoring -- this was very invasive," Scott-Railton said.
The hacking allegations have been dubbed by Polish media as a "Polish Watergate" -- referring to the scandal that emerged after former US president Richard Nixon's reelection campaign, which ultimately led to his resignation in 1974.
Poland has rejected accusations that it had used Pegasus spyware for political ends.
But Stanislaw Zaryn, spokesman for the ministry in charge of the country's secret services, did not confirm or deny if Poland used Pegasus.
The NSO Group, the Israeli owner of Pegasus, told AFP it is sold "only to legitimate law enforcement agencies who use these systems under warrants to fight criminals, terrorists and corruption."
In July, controversy erupted around Pegasus, after a collaborative investigation by several media outlets reported that governments used Pegasus to spy on activists, journalists, lawyers and politicians.
US authorities last month blacklisted NSO by restricting exports to it from American groups over allegations the Israeli firm "enabled foreign governments to conduct transnational repression."
Polish opposition leader Donald Tusk on Tuesday said recent reports that the government spied on its opponents represented the country's biggest "crisis for democracy" since the end of communism.
Tusk, a former EU Council president, also called for a parliamentary inquiry into the allegations.