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 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.