Police on Wednesday entered the headquarters of Spanish Prime Minister Pedro Sánchez's Spanish Socialist Workers' Party (PSOE) to acquire documents, a court in Madrid announced.
Initial media reports had referred to the large-scale police operation as a search, but the court said it was a "request for documentation."
The homes and offices of several former high-ranking PSOE officials were also searched on Wednesday, or instructed to provide documents.
State broadcaster RTVE described the operation as a "political earthquake."
According to the court statement, the police operation is linked to an investigation into former PSOE official Santos Cerdán and others on suspicion of corruption, influence-peddling and the award of state contracts in exchange for money.
Cerdán resigned from his post with the PSOE when the scandal broke in June last year.
The police operation was not the first to target the PSOE headquarters. The left-wing government has been rocked by several corruption scandals.
No allegations have thus far been made against Sánchez, who again pledged full cooperation following an audience with Pope Leo XIV in the Vatican.
Sánchez emphatically rejected a call from the conservative opposition for early elections, noting that the Cerdán case referred to last year. "But if there are new cases, we will act with the same determination," he said.
Alberto Núñez Feijóo, head of the conservative opposition People's Party (PP), accused the government of "systemic corruption."
Former transport minister in the Sánchez government, José Luis Ábalos, and his former adviser Koldo García are in custody while investigations proceed into corruption related to the purchase of masks during the coronavirus pandemic.
Corruption investigations are also proceeding into Sánchez's wife, Begoña Gómez, and into his brother David Sánchez.
Former PSOE prime minister José Luis Rodríguez Zapatero, a close Sánchez associate, is also under investigation for corruption for state funding provided to an airline during the pandemic.
