Spain will investigate claims that dozens of Catalonian separatists were subject to systematic surveillance through Pegasus spyware, in a scandal that has threatened to topple the government, the Spanish government announced Sunday.

Investigators at Canada's Citizen Lab said the mobile phones of at least 65 Catalan politicians – including the region's current leader – had been affected.

In most cases the Pegasus malware, made by Israel's NSO Group, had been used following Catalonia's controversial 2017 independence referendum declared illegal by Madrid, the group said.

Citizen Lab, which focuses on high-tech human rights abuses, said it could not directly attribute the spying operations, but that circumstantial evidence pointed to Spanish authorities.

Catalan leaders have accused the Spanish government of being behind the illegal operation.

"The government has a clear conscience and nothing to hide," said Spain's presidency minister Felix Bolanos, announcing a series of investigations into the affair.

Bolanos promised an "internal investigation" within the National Intelligence Centre which would report to a parliamentary commission allowing lawmakers to access classified information.

Spain's rights ombudsman will also open an independent investigation, he added, vowing to "collaborate with justice by declassifying documents if necessary."

Bolanos announced the investigations after an emergency meeting with his counterpart in Catalonia's pro-independence regional administration, Laura Vilagra.

Vilagra called the promises "vague," saying they did not go far enough. Catalonia's executive continues to demand the identification of those responsible and their resignations.

The pro-independence Catalan party propping up Prime Minister Pedro Sanchez's minority socialist coalition could not "guarantee" their support amid the ongoing uncertainty, she said. Catalan and Basque separatist parties – including Catalan leader Pere Aragones's left-wing republican formation – are part of Spain's coalition government.

Political tensions reignited

The Citizen Lab, a research center at Canada's University of Toronto, said almost all of the spying took place between 2017 and 2020 in the wake of Catalonia's independence bid that plunged Spain into its worst political crisis in years.

Among those targeted by the spyware were Aragones, ex-regional leaders Quim Torra and Artur Mas, members of the Catalan parliament and independent civil society organizations, the group said.

Smartphones targeted by 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 them knowing.

The malware was at the center of a row in 2021 after a collaborative investigation by several media outlets reported that governments used it to spy on activists, journalists, lawyers and politicians.

Catalonia in northeast Spain has been for several years at the center of a political crisis between separatists, who control the executive and the regional parliament, and the central government in Madrid. Tensions had eased since dialogue began between Sanchez's government and the regional authorities in 2020 and the granting of pardons to nine pro-independence leaders last year.