Mexico's president said on Thursday that an elite unit which worked on narcotics investigations with the United States was closed last year, confirming a Reuters report, and alleging the group had been infiltrated by criminals.
On Tuesday, Reuters reported Mexico had disbanded the group that for a quarter of a century worked hand-in-hand with the U.S. Drug Enforcement Administration (DEA) to tackle organized crime.
The closure complicates U.S. efforts to help combat organized crime inside Mexico, one of the epicenters of the multi-billion dollar global narcotics trade, and makes it harder to catch and prosecute cartel leaders, security experts say.
Speaking at a regular news conference, President Andres Manuel Lopez Obrador said the unit was shut down "over a year ago" and that cooperation with international security bodies was continuing, provided Mexico's sovereignty was respected.
"That group, which was supposedly a high-level strategic group, was infiltrated (by criminals)," he said.
The president said he had "put in order" Mexico's relations with the United States. Past administrations had allowed those ties to infringe on Mexico's sovereignty, he argued.
"It's another kind of relationship now," he said.
In Mexico, the officers in the Sensitive Investigative Units (SIU) police unit were considered many of the country's best and worked on the biggest cases such as the 2016 capture of capo Joaquin "El Chapo" Guzman, erstwhile boss of the Sinaloa Cartel.
Though the SIU's reputation was damaged when its former chief, Ivan Reyes Arzate, was detained in 2017 and pleaded guilty in a U.S. court to taking bribes to leak tips to a drug gang, the unit was seen as vital by DEA officials who needed Mexican officers to help their investigations in the country.
Following the Reuters report, U.S. congressman Michael McCaul - the head Republican on the House Committee on Foreign Affairs - said he was concerned by the Mexican decision.
"Mexico's continued undermining of security cooperation is deeply unsettling," he said on Twitter. "Both nations benefit from tackling the narcotics trade."
(Reporting by Kylie Madry, Valentine Hilaire, writing by Stephen Eisenhammer, editing by Alexandra Hudson)