Mexican federal prosecutors charged a former state prosecutor with treason on Wednesday after accusing him of allowing US personnel to take part in a drug operation in northern Mexico without the federal government's approval, Reuters reported from Mexico City on October 21. Authorities dusted off one of the country's gravest and least-used criminal charges against former Chihuahua Attorney General Cesar Jauregui, in a case Reuters said could reshape how Mexican officials work with US security forces.

Prosecutors allege Jauregui allowed US agents to participate in an April raid on a suspected drug lab in Chihuahua, a border state that has long been central to Mexico's fight against organised crime, Reuters reported. The raid only came to light after US agents were killed in a car crash returning from the scene. Border Report reported that two US officials and two Mexican officials died in an April 19 vehicle crash following the operation, and that President Claudia Sheinbaum said her federal government had been unaware of the Americans' involvement.

A judge ordered Jauregui held in pretrial detention while the court decides whether there is enough evidence to formally proceed with a criminal case, and a follow-up hearing is scheduled for Saturday, according to a statement from the Attorney General's Office reported by Reuters. Attorney General Ernestina Godoy said Jauregui allowed foreign agents to carry out activities reserved for Mexican authorities and failed to share information with federal officials as required, Reuters reported.

Jauregui has denied authorising the Americans' participation. His attorney, Villasana, disputed the federal accusation after the hearing, saying the evidence presented did not directly connect his client to the alleged conduct, Forbes Mexico reported, according to Border Report. The detention order does not constitute a conviction, and Jauregui remains presumed innocent, Border Report noted from the federal prosecutors' statement.

The case has become a test of federal control over security cooperation with Washington. Sheinbaum has said Mexico welcomes intelligence sharing and cooperation against organised crime but does not permit US agents or military forces to participate directly in operations on Mexican territory, Border Report reported. She also denied that there was a political pact with Chihuahua's opposition Governor Maru Campos to bring Jauregui down, saying, in SonoraPresente's report of her remarks: 'Justice is above even politics.' Analyst Matias Gomez Leautaud of Eurasia Group told Reuters the treason charge 'seeks to set a precedent and prevent cooperation between (Mexican) states and the US government without the federal government's coordination and approval'.