A far-reaching Pegasus scandal in Mexico went to court Monday with prosecutors focused on how the spyware targeted one of the country’s most celebrated investigative journalists and other prominent Mexicans, including the billionaire Carlos Slim.

The journalist, Carmen Aristegui, was allegedly spied on during the Enrique Peña Nieto administration, which ran from 2012 to 2018. She is the first witness in a sprawling trial with a large number of alleged victims. It could run for months, according to reporting from the Spanish newspaper El Pais.

The Mexican Pegasus case centers on how the potent spyware manufactured by the Israeli firm NSO Group was used to surveil potentially thousands of victims across multiple Mexican presidential administrations, El Pais reported. Pegasus gives users the ability to see the contents of a victim’s phone as well as activate its camera and microphone for real time spying, according to privacy experts.

Government-led spyware campaigns have rocked Europe in recent years with major incidents including alleged government spying on opposition politicians in Poland and a Russian journalist to cite two of many incidents that have spanned Greece, Spain and Hungary, among other countries.

A key prosecution witness — a whistleblower known as Zeus — told the court Monday that Peña Nieto and his staff ordered the alleged targeting of Aristegui as well as Slim and mining mogul Germán Larrea, according to El Pais.

Peña Nieto is not the only Mexican politician implicated in the scandal. A recently completed investigation by the Digital Rights Defense Network showed that during the current administration government agencies also used Pegasus to spy on at least three people. Mexican journalist Ricardo Raphael and human rights activist Raymundo Ramos are among the alleged victims.

Aristegui — one of the country’s leading journalists who is known for her critical reports on the government — was one of the few victims to push for a trial, El Pais reported. In court Monday, she demanded justice, saying she hoped the Attorney General’s Office has “enough elements to clarify the case,” El Pais reported

Early in the Peña Nieto administration, the journalist and her investigative team reported on alleged corruption among the president and his staff, ultimately publishing a story about the relationship between Peña Nieto and a business conglomerate. According to El Pais, the story focused on an expensive home owned by Peña Nieto which was registered in the name of the business conglomerate and protected by the army.

After the report was published, Pegasus was used to monitor Aristegui’s phone, prosecutors allege. Aristegui uncovered thousands of documents about the use of Pegasus to target her, El Pais reported, and broadcast her allegations on her news network.

The whistleblower, Zeus, was Aristegui’s source. He reported the spying had been executed by KBH business group, a supplier of Pegasus in Mexico, El Pais reported.

Aristegui gave the documents to the Mexican Attorney General’s office, which ultimately arrested the man who allegedly oversaw the spying, Juan Carlos García Rivera, a staffer at a KBH subsidiary.

Garcia Rivera could potentially face 16 years in prison for his role in the scheme, according to El Pais.