EL CHAPO’S ruthless cartel used a hacker to break into Mexico City’s CCTV system and track down FBI informants — before having them killed.

An alarming report from the US Justice Department discloses that the Sinaloa Cartel, previously led by Joaquín “El Chapo” Guzmán, employed a technology expert to spy on American operatives and uncover their informants.

The hacker hacked into Mexico City’s camera network and phone records in 2018, tailing an FBI assistant legal attaché (ALAT) at the US embassy.

Armed with this intel, the cartel was able to “intimidate and, in some instances, kill potential sources or cooperating witnesses,” the report said.

The Justice Department stated: “According to the FBI, the hacker not only breached the ALAT’s phone but also infiltrated Mexico City’s camera network, used these cameras to track the ALAT’s movements throughout the city, and identified individuals the ALAT interacted with.”

The findings shine a harsh light on how cartels are now using cutting-edge tech to stay a step ahead of law enforcement.

The report cautioned that advancements in technology have “made it easier than ever for less advanced countries and criminal organizations to detect and exploit weaknesses” in government systems.

It comes as Mexico’s cops desperately try to catch up.

In Chiapas this week, police unveiled armed drones to take on cartels fighting for smuggling routes along the Guatemalan border.

Just weeks ago, the same force sparked a diplomatic storm by chasing gunmen into Guatemala and engaging in a wild street shootout.

The Sinaloa Cartel — once commanded by El Chapo, who’s now locked up in the US — remains locked in a bloody battle with the Jalisco New Generation Cartel.

Meanwhile, a new breed of younger, tech-savvy narcos is ramping up tactics like cryptocurrency laundering and state-of-the-art surveillance.

“The cartels run a multi-billion-dollar global enterprise and utilize sophisticated technology to enhance their business operations,” said Derek Maltz, former acting DEA chief.

“They utilize state-of-art sophisticated surveillance techniques to identify law enforcement activities and their adversaries.”

The FBI says it’s drafting a plan to plug these glaring security gaps, including more training for agents.

But the Justice Department report warned the threat is so severe that some in the FBI and CIA call it “existential”.

Mexico’s long-running drug war rages on with no end in sight.

More than 400,000 people have been killed since the government first declared war on the cartels in 2006, and tens of thousands more have vanished without a trace.

Despite high-profile arrests and military crackdowns, groups like Sinaloa and Jalisco New Generation continue to expand their reach, both at home and across borders.

In the US, the stakes are equally dire.

Authorities have repeatedly blamed Mexican cartels for driving the fentanyl crisis, which has fuelled a record surge in overdose deaths.

Washington has labelled these syndicates “foreign terrorist organisations” in everything but official designation, ramping up efforts to cripple their finances and supply chains.