Alfonso Rus (center), former chief of the Diputación de Valencia, was arrested on Tuesday. Mònica Torres

Spanish authorities have launched a major raid against political corruption in the Valencia region.

By 1pm on Tuesday, 24 people had been arrested as part of Operation Taula, which is targeting local governments in the provinces of Valencia, Alicante and Castellón as well as the Diputación de Valencia – the provincial authority. The operation is focusing heavily on Valencia province, however.

All of the detainees have ties to the Popular Party (PP), which governed in the Mediterranean region for two decades until May 2015, when local and regional elections resulted in a political shift to the left.

The scope of the irregular activities, which went on for years, was described by one source as “humongous”

Five more people have been placed under official investigation but were not arrested.

One of the suspects, according to sources familiar with the investigation, is Alfonso Rus, a former Diputación chief and ex-mayor of Xàtiva. Another is María José Alcón, who used to work as an advisor to former Valencia mayor Rita Barberá. Alcón is married to Alfonso Grau, a former deputy mayor of Valencia who is a defendant in the ongoing Noos trial, which has also ensnared a member of the Spanish royal family, King Felipe’s sister Cristina.

Besides the arrests, the Civil Guard were on Tuesday conducting 33 searches in private homes, company headquarters, foundations and a sports club.

The same sources said that everyone under investigation is believed to have participated in a corrupt network that charged commissions in exchange for granting public contracts. These sources said investigators are also contemplating the possibility that part of the money was used for illegal party financing on the part of the Valencian branch of the PP.

The suspects may have incurred in offenses of embezzlement, bribery of public officials, influence peddling and money laundering, among other crimes. The scope of the irregular activities, which went on for years, was described by one source as “enormous.”

The Civil Guard entered Valencia City Hall at 10am on Tuesday and reviewed information in the power of the PP group. Its secretary, María del Carmen García Fuster, was arrested.

The regional PP has temporarily suspended everyone involved in the operation from membership.

One of the suspects in the case, former Diputación deputy chief Máximo Caturla, was a top official at a public corporation called Ciegsa, which built schools throughout the region. The new regional administration recently revealed that these construction projects had cost overruns of over one billion euros.

Meanwhile, Alfonso Rus was forced to resign from the Diputación last April, just one month before the elections, when secret recordings emerged in which he was heard counting wads of cash.

That probe began when the regional leftist party Esquerra Unida (United Left) filed a complaint with the anti-corruption attorney in July 2014, pointing to a corrupt network involving Rus and Marcos Benavent, the former manager of public corporation Imelsa, as well as several other PP officials.

Marcos Benavent, it emerged, had secretly recorded private conversations for years, including one in which Rus is heard counting the money from an alleged bribe.

Those recordings were sent to the attorney’s office, and Benavent has since appeared in court sporting a long white beard, dressed like an anti-capitalist activist and expressing contrition at his past life.

“I want to ask for public forgiveness,” he said at a court appearance on May 26. “I am very sorry. I will accept whatever I have to accept, whatever guilt is assigned to me, even prison. And I will try to give back everything that I took.”

Benavent, who said about himself that “I used to be a money junkie,” also warned that “the recordings are real” and that “the shit’s about to hit the fan.”