The head of Uruguayan President Luis Lacalle Pou’s personal security detail was arrested on Monday at the presidential residence on charges of falsifying documents.

News of the arrest of security chief Alejandro Astesiano, who was detained shortly after returning to Uruguay from a trip with Lacalle Pou and his sons, appeared to leave the president shaken.

“I’m as surprised as you all are,” Lacalle Pou said at a news conference he called on Monday in the capital of Montevideo. “I’m sick,” the president added.

At the center of the investigation led by public prosecutor Gabriel Fosatti are allegations that Astesiano sold fake Uruguayan passports to Russian citizens.

According to police sources cited by local media, Astesiano had contacts that allowed him to process the required documentation to acquire the passports and sell them to Russians.

Lacalle Pou denied reports that Astesiano had a criminal record. On Monday afternoon, several local media outlets reported that there were prior inquiries into the security chief for 20 police matters such as fraud, misappropriation and theft, among others.