Luxembourg Foreign Affairs Minister Jean Asselborn on Wednesday published a copy of a letter he sent to directors of Luxembourg-based units of Israeli company NSO expressing his grave concerns over allegations of espionage.
The use of the software, called Pegasus and developed by a private Israeli company NSO group, was reported Sunday by the Washington Post, the Guardian, Le Monde and other news outlets who collaborated on an investigation into a data leak.
The letter also reminded the directors of the importance to adhering to Luxembourg laws and protecting privacy rights.
NSO has several units registered in Luxembourg, such as Q Cyber Technologies and Novalpina Capital Partners.
NSO has said its products are intended only for use by government intelligence and law enforcement agencies to fight terrorism and crime.
Since the story broke earlier this week it gained traction internationally, with some countries either demanding or opening investigations.
On Tuesday, prosecutors in Paris said they had opened a probe into allegations that Moroccan intelligence services used the Israeli-made malware Pegasus to spy on several French journalists.
Meanwhile, Indian opposition parties disrupted parliament on Tuesday, demanding an investigation into reports that the government used Pegasus spyware to snoop on scores of journalists, activists and politicians, including the main opposition leader Rahul Gandhi.