A former Mexican presidential cabinet member has been convicted in the United States of taking enormous bribes to protect the violent drug cartels he was tasked with combatting.

Under tight security, an anonymous New York federal court jury deliberated for three days before reaching a verdict in the drug-trafficking case against Mexico’s former Security of Public Secretary Genaro Garcia Luna.

He is the highest-ranking current or former Mexican official ever to be tried in the US.

Garcia Luna, who denied the allegations, headed Mexico’s federal police and then was its top public safety official from 2006 to 2012. His lawyers said the charges were based on lies from criminals who wanted to punish his drug-fighting efforts and to get sentencing breaks for themselves by helping prosecutors.

Garcia Luna showed no apparent reaction on hearing the verdict.

The case had political ramifications on both sides of the border. Testimony aired a secondhand claim that former Mexican President Felipe Calderon sought to shield the notorious Sinaloa cocaine cartel kingpin Joaquin “El Chapo” Guzman against a major rival. Calderon, meanwhile, has called the allegation “absurd” and “an absolute lie”.

Jurors also learned that Garcia Luna met with high-level US politicians and other officials who considered him a key cartel-fighting partner as Washington embarked on a $1.6bn push to beef up Mexican law enforcement and stem the flow of drugs.

The Americans were not accused of wrongdoing, and although suspicions long swirled around Garcia Luna, the trial did not delve into the extent of US officials’ knowledge about them before his 2019 arrest.

Current Mexican President Andres Manuel Lopez Obrador has, however, pointedly suggested Washington should investigate its own law enforcement and intelligence officials who worked with Garcia Luna during Calderon’s administration.

A roster of ex-smugglers and former Mexican officials testified that Garcia Luna took millions of dollars in cartel cash, met with major traffickers and kept law enforcement at bay.

He was “the best investment they had”, said Sergio “El Grande” Villarreal Barragan, a former federal police officer who worked for cartels on the side and later as his main job. “We had absolutely no problems with our activities.”

He and other witnesses said that, on Garcia Luna’s watch, police tipped traffickers about upcoming raids, ensured cocaine could pass freely through the country, colluded with cartels to raid rivals and did other favours.

One ex-smuggler said Garcia Luna shared a document that reflected information from US law enforcement about a huge cocaine shipment seized in Mexico around 2007.

Garcia Luna, 54, did not testify at the trial, though his wife took the stand in an apparent effort to portray their assets in Mexico as legitimately acquired and upper-middle-class but not lavish. The couple moved to Miami in 2012 when the Mexican administration changed, and Garcia Luna became a consultant on security issues.

His lawyers emphasised that prosecutors’ case relied on testimony from admitted lawbreakers, without recordings, messages or a documented money trail to corroborate their accusations.

“Nothing backs up what these killers, torturers, fraudsters and epic narcotics traffickers claimed about Genaro Garcia Luna,” defence lawyer Cesar de Castro said in a closing argument.

Garcia Luna was convicted on charges that include engaging in a continuing criminal enterprise, which carries a potential sentencing range of 20 years to life in prison. He also was convicted of other charges, including cocaine distribution and cocaine conspiracy. His sentencing is set for June 27.

The trial was peppered with glimpses of such narco-extravagances as a private zoo with a lion, a hippo, white tigers and more. Jurors heard about tonnes of cocaine moving through Latin America in shipping containers, go-fast boats, private jets, planes, trains and even submarines.

And there were horrific reminders of the extraordinary violence those drugs fueled.

Witnesses described cartel killings and kidnappings, allegedly including an abduction of Garcia Luna himself. There was testimony about police officers being slaughtered and drug-world rivals being dismembered, skinned and dangled from bridges as cartel factions fought each other while buying police protection.

Witnesses described delivering Garcia Luna to meetings with cartel leaders in settings ranging from a country house to a car wash. They also recounted trips to collect boxes and bags full of drug money at safe houses, a warehouse full of cocaine and a fancy Mexico City restaurant.

One ex-smuggler, Oscar “El Lobo” Nava Valencia, said he personally heard Garcia Luna and a then-top police official say they would “stand with us” during a meeting with Guzman’s associates amid a cartel civil war. That sit-down alone cost the drug gang $3m, Nava Valencia said.

Garcia Luna was arrested after testimony about his alleged corruption emerged at Guzman’s high-profile trial about four years ago in the same New York courtroom.

The former politician also faces various Mexican arrest warrants and charges relating to government technology contracts, prison contracting and the bungled US “Fast and Furious” investigation, which looked into suspicions that guns were illegally making their way from the US to Mexican drug cartels.

The Mexican government has also filed a civil suit against Garcia Luna and his alleged associates and businesses in Florida, seeking to recover $700m Mexico claims he garnered through corruption.

Lopez Obrador has given updates on the New York trial at his daily press conferences, calling Garcia Luna corrupt but noting it was up to the jury to decide whether he was guilty.