After the U.S. government’s announcement of an alleged Iranian plot to hire Mexican drug traffickers to kill the Saudi ambassador, some Mexican lawmakers are taking a critical look at the activities of U.S. drug enforcement agents in the country.

At a hearing before the Public Security Commission of Mexico’s House of Representatives, Public Safety Secretary Genaro Garcia Luna faced tough questioning about the scale of operations of the U.S. Drug Enforcement Administration (DEA) on Mexican soil. According to Proceso magazine, legislators from the left-wing Party of the Democratic Revolution (PRD) asked Garcia for a clarification of the DEA’s operations.

In response, the secretary downplayed the presence of the DEA, saying the agency is not authorized to conduct actions on its own. “We only exchange information, there is no independent operation,” he said.

The remarks come after reports surfaced in the U.S. media in August of a scheme to send intelligence agents and retired military personnel to work with Mexican military officials at an intelligence fusion center at an undisclosed location in that country. As InSight Crime has reported, this was a controversial announcement in Mexico, and has sparked a backlash among officials who see the deepening of security ties as an affront to sovereignty.