Experts included Fernand de Varennes, the special rapporteur on freedom of peaceful assembly and of association, and Irene Kahn, the special rapporteur on freedom of opinion and expression.
"Spanish authorities must conduct a full, fair, and effective investigation into these allegations, publish the findings and stop any unlawful interference into the fundamental rights of the Catalan minority activists in Spain," the UN Human Rights Office of the High Commissioner (OHCHR) quoted the experts on the website.
"We are looking forward to the outcomes of the ongoing judicial investigation... We are also deeply concerned by what appears to be a very troubling interference into the human rights of Catalan leaders and other minority activists to freely hold and express their views, exchange information and ideas, assemble peacefully and participate in associations. They are entitled to a private life, the privacy of correspondence and to be treated equally before the law."
According to the statement, devices of at least 65 Catalan minority leaders, members of the European Parliament, legislators, jurists, and members of civil society organizations, were allegedly targeted by a "complex and sophisticated spying programme" between 2017 and 2020.
Experts said "most incidents of spying against Catalan leaders and activists took place in 2017, soon after the region’s bid for independence." These include SMS-based attacks, containing malicious links designed to trick targets into clicking on them, and highly personalized official notifications from Spanish government entities.
Officials also called for a global moratorium on the sale and transfer of surveillance technologies.
"We further wish to reiterate our call for a global moratorium on the sale and transfer of surveillance technology, until robust regulations are in place that guarantee its use in compliance with international human rights standards. We urge Spain to join this global moratorium, that was also joined by then High Commissioner for Human Rights, Michelle Bachelet," the experts said.
In the October 2017 referendum, which Madrid called illegal, over 90% of voters supported Catalonia's independence. The Spanish government refused to recognize the results of the vote, the turnout for which fell below 50% and stood at 43%.
In October 2019, the Supreme Court sentenced 12 Catalan politicians and activists for organizing an unauthorized referendum on independence and issuing a unilateral declaration of independence. Nine people were found guilty of mutiny and received sentences ranging from nine to 13 years in prison. Three were found guilty of insubordination and given fines.
The international scandal over Pegasus spyware, used by the Israeli authorities to spy on terrorists, broke in July 2021 after a joint media investigation unveiled that the spyware had also been used to keep an eye on politicians, businessmen, activists, journalists, and opposition figures around the world.