Months after a deadly car wreck revealed the CIA’s participation in a raid on a Chihuahua drug lab, authorities arrested César Jáuregui, Chihuahua’s former attorney general, for allegedly allowing US spies to participate in the operation without permission from the Mexican government.

Gilberto Loya Chávez, the acting head of the Chihuahua Attorney General’s Office, said in a video message that Jáuregui is under investigation for unlawful exercise of public service and conspiracy by public officials. Jáuregui is due to appear before a judge, Loya Chávez added, but did not say when.

The arrest, the official explained, came after the Attorney General’s Office concluded that there had been misconduct in an April operation in which state officials dismantled a clandestine drug-manufacturing laboratory.

The CIA’s participation came to light soon after the raid on April 19. That day, while he was still attorney general, Jáuregui himself announced that four people had died in a car crash as they were returning from a drug raid in northern Chihuahua: two Mexican law enforcement officials and two Americans, whom he identified as instructors from the US Embassy in Mexico City.

Days later, CNN and other media outlets revealed that the two Americans were not just embassy workers: they were CIA agents. The agency has significantly expanded its clandestine anti-cartel operations in the country during Trump’s second term – including assassinations of alleged cartel members and drone flights over Mexican territory.

On Saturday, Loya Chávez was careful to say that the issue at hand was not the drug raid itself, but rather the participation of US officials outside the bounds of Mexican law.

“This action does not disregard the work of the State Investigation Agency, the State Attorney General’s Office, or the Armed Forces in dismantling the clandestine laboratory, because it is of course a very significant result in the fight against organized crime,” Loya Chávez said. “What is being investigated is the way this operation was conducted, the failure to observe the chain of command and the applicable protocols.”“A good result does not justify breaking the law,” the official added.

CNN has contacted Jáuregui’s office to find out whether he already has legal representation and whether he has entered a plea.

The presence of CIA agents in the operation incensed the government of President Claudia Sheinbaum, which took Chihuahua authorities to task for failing to give prior notice and coordinate with their federal counterparts, as required by Mexican law. Sheinbaum has insisted ever since that the situation had to be investigated to determine whether any crime had been committed.

The president said at the time that her office had been unaware that state officials in Chihuahua and the US government were collaborating independently.

“The relationship is federal, not state,” Sheinbaum said. “They must have authorization from the federal government for this collaboration, which necessarily takes place at the state level, as established by the Constitution.”Soon after, Chihuahua Governor María Eugenia Campos ordered the creation of a unit to investigate the case.

On April 27, in her first report on the matter, special prosecutor Wendy Chávez said there were indications that the director of Chihuahua’s state security agency, who died in the car crash, had “possible unofficial collaboration” with the US agents and did not inform his superiors that they would be taking part in the operation.

Jáuregui resigned as attorney general that same day, stating that he was accepting “political responsibility” for the tensions the matter had generated.

“There were omissions both in the information provided and in the institutional handling of the points of contact with these individuals,” he said.

Until his arrest on Saturday, Jáuregui had been seeking the conservative National Action Party nomination for mayor of Chihuahua, the state’s capital.