By Alyssa McMurtry

MADRID

Spanish police raided the Madrid headquarters of Spain’s ruling Popular Party late Thursday as part of an ongoing investigation corruption, local media reported.

The Civil Guard searched the local offices for evidence of illegal party financing.

The operation is related to an investigation into a bid-rigging ring allegedly used by corrupt politicians to collect bribes for awarding public contracts. Prosecutors suspect public contracts worth up to 250 million euros ($281 million) were granted by corrupt officials.

The investigation -- dubbed Operation Punica -- led to the arrest of 35 prominent mayors, politicians and business people in October 2014 in several Spanish regions.

The raid followed the discovery of notes by Francisco Granados, a major suspect who was once the right-hand man to Esperanza Aguirre, the former Madrid president.

Javier Maroto, a member of the party’s national board, called for a “purge” on corruption in the Popular Party, saying it was needed “no matter who it takes out”.

However, Aguirre, who heads the party’s Madrid branch, said there was “no evidence and no proof of any kind of illegal financing”. She added that the party was fully cooperating with police.

The scandal is one of several currently plaguing Prime Minister Mariano Rajoy’s party.

In January, police arrested 24 high-profile Popular Party politicians and businessmen in Valencia over allegations of operating a similar corruption ring. Several of the party’s politicians are implicated in the Princess Cristina trial, in which the sister of the Spanish king is accused of collaborating in another ring of illegal kickbacks.

The Popular Party won the Spanish general election in December but lost its parliamentary majority. A functioning government is still to be formed.