Mexico has arrested former Chihuahua Attorney General Cesar Jauregui on suspicion of treason, following allegations that he permitted foreign agents to participate in a security operation without the required legal approval, Mexican Attorney General Ernestina Godoy announced Saturday.

Investigators suspect Jauregui authorized U.S. personnel to join an April operation targeting a suspected drug laboratory in Chihuahua, a northern Mexican state bordering the United States. Prosecutors say the participation was unauthorized under Mexican law.

The case has drawn attention to the sensitive question of U.S. involvement in Mexico’s fight against drug trafficking, particularly after two American intelligence officers reportedly died in a vehicle crash earlier this year.

In April, Washington confirmed the deaths of two employees assigned to its embassy in Mexico City but did not publicly identify their agencies. Sources familiar with the incident said both were CIA officers engaged in counter-narcotics work.

The deaths intensified scrutiny of cooperation between the two countries. President Claudia Sheinbaum subsequently emphasized that Mexico supports intelligence exchanges and joint efforts against organized crime but does not allow American agents or military personnel to take part directly in operations on Mexican soil.

Godoy said investigators believe the former prosecutor may have violated national security laws by allowing foreign personnel to participate in activities reserved for Mexican security forces.

“The investigation determined that Cesar N may have engaged in conduct that could possibly ​constitute the crime of ​treason in matters ⁠of national security because he allegedly allowed foreign individuals to intervene without authorization on Mexican territory and take part in ​actions that correspond exclusively to national security forces,” Godoy said ​in a ⁠video message on Saturday.

Authorities referred to the suspect as “Cesar N,” following Mexico’s customary practice of withholding a suspect’s complete surname during criminal proceedings.

Godoy confirmed that a federal judge had approved an arrest warrant after investigators spent several months examining the allegations.

Jauregui was not immediately available for comment. The U.S. embassy declined to comment on Saturday.