After 35 years of inaction by the Spanish tribunals, it was concluded that Zabalza died as result of torture inflicted on him by Civil Guard operatives at the headquarters of Intxaurrondo in San Sebastián.

A few days later, the authorities responsible for Zabalza's police custody announced that he had escaped by jumping into the river Bidasoa at the point where it passes through the town of Endarlatsa, in the municipality of Lesaka, when he was being driven to identify an ETA hideout,[9] which was never found.

[12] The Guardia Civil agents responsible for his custody (lieutenants Gonzalo Pérez García and Arturo Espejo Valero, and the guard Fernando Castañeda Valls)[13] were prosecuted during the first phase of the investigation.

[13] In 1985, the journalist José Macca, at Diario 16, published the confession of the former Guardia Civil agent Vicente Soria asserting that he had seen Zabalza's corpse in an elevator in the Intxaurrondo barracks.

This time, in 2000, the smuggler Pedro Luis Miguéliz Dabadie («Txofo»)[14] testified in a trial in San Sebastián that the former Guardia Civil Enrique Dorado Villalobos had told him that Zabaltza had died in the barracks during the detention, after torture inflicted by himself and the also former agent Felipe Bayo Leal, both of whom were convicted first in the Lasa and Zabala case.

[16] On March 1, 2021, all of the political parties in the Navarre Parliament joined together to demand an investigation into Zabalza's death:"The Parliament of Navarre demands, that, given the publication of the recordings of the Captain Gómez Nieto of the Guardia Civil and the then Chief Colonel of the Centro Superior de Información de la Defensa (CESID) Juan Alberto Perote, they should be thoroughly investigated with the objective of finding out the truth about the death” of Zabalza.

[17] Bakartxo Ruiz, the spokesperson for EH Bildu noted that the recordings “make clear not just what happened in individual circumstances, but also suggest what everyone in this country knows: that torture has been used systematically with political objectives and has been hidden with absolute impunity".

[19] The case originated in events that took place the previous year, on December 17, when they had published in both papers the death notices of Mikel Zabalza and Quim Sànchez, a Catalan pro-independence political activist who died when working with explosives.

[20] As part of the same case, Juli Palou i Mínguez, Ismael Durà i Guimerà, Joaquim Roig i Ortiz, and Josep Ramon Freixes i Sentís, all of whom were members of pro-independence organizations and parties PSAN, MDT, IPC and CSPC were accused of paying for the announcements.

With respect to the various failed judicial attempts, last summer, the Spanish Constitutional Court annulled almost the entire Navarre law of 2015 that recognized and sought to give reparations to victims of far-right violence.

Similarly, earlier in the week, the High Court of Justice in Navarre paralyzed the calling of grants to universities that document cases of torture and abuse by these groups.

On April 25, 2016, the Spanish delegate to Navarre Carmen Alba sent a letter demanding that the city council in Agoitz eliminate, within the month, a mural in homage to the murdered young man, which had been painted two or three years earlier in the Market Square.

Another reaction to the letter came from the local representative of the Spanish People's Party, Javier García, who said that “the only thing that the Delegate was doing was demand that the current law be followed” which requires «that any graffiti or symobology linked with the terrorist network must be removed».