The highly-anticipated trial of notorious Mexican drug lord Joaquín ‘El Chapo’ Guzman began this week in Brooklyn, New York.

‘El Chapo’ – meaning ‘Shorty’ – was arrested while on the run in Mexico in January 2016, after escaping from prison for the second time in his career.

Only one week in to what is expected to be a four month long trial, witnesses have already shed a whole new light on the inner workings of the Sinaloa cartel - although 61-year-old Guzman's lawyers have claimed he did not play the integral role prosecutors allege.

Here are some of the key moments from this week’s trial:

It was delayed

Day one of the hearing was delayed due to a jury member being excused. Amid extraordinary security measures, one of the 12 jurors – all of whom will remain anonymous, was excused due to alleged anxiety.

The defence accused Mexican presidents of taking bribes from the Sinaloa cartel

In his opening statement, Guzman’s defence attorney, Jeffrey Lichtman, said his client was not the real leader of the Sinaloa Cartel and shifted blame onto Ismael “El Mayo” Zambada, another alleged drug trafficker in the cartel’s leadership. Zambada remains on the loose in Mexico, Mr Lichtman claimed, because of bribes that “go up to the very top,” including hundreds of millions of dollars paid to the current and former presidents of Mexico.

A spokesman for Mexico’s President Enrique Pena Nieto called the allegations “completely false and defamatory.” Former President Felipe Calderon dismissed them as “absolutely false and reckless.”

Joaquin GuzmanAKA El Chapo

Drug trafficking tunnels from Mexico to US

The jury was shown a video of the tunnel that was allegedly used to smuggle cocaine, marijuana, meth and heroin.

The tunnel was half the length of a football field and big enough that a 5-foot-8 inch man barely had to lower his head to walk through it. It had electric lights and a hydraulic system to lift away flooring that was covered by a pool table. Authorities say tons of cocaine were rolled through on carts.

Defence lawyers claim Guzman is being framed.

Brother of key cartel member gives testimony

Jesus ‘El Rey’ Zambada, appeared as a government witness to testify against Guzman.

‘El Rey’ is the younger brother of what prosecutors say is Guzman’s longtime partner in the Sinaloa cartel, Ismael ‘El Mayo’ Zambada. In his lengthy testimony, ‘El Rey’ told the court his brother worked with ‘El Chapo’ and others to form the Sinaloa cartel, smuggling tons of drugs from Mexico to the US.

In the four hour testimony, Zambada also alleged his brother and Guzman used armies of assassins to murder their enemies, Vice reported.

Support free-thinking journalism and attend Independent events

War with other drug gangs

Zambada spoke at length about the violent conflict between the Sinaloa cartel and the Tijuana cartel. ‘El Rey’ said the rival gang led by brothers Benjamin and Ramon Arellano-Felix, started the war by refusing to share their territory, according to Vice.

Assassination of Catholic Church official

Zambada also spoke about the killing of Cardinal Juan Posadas Ocampo in 1993. He claimed that Arellano Felix, a rival to Guzman from the Tijuana drug cartel, killed the cardinal at an airport in Guadalajara while trying to murder Joaquin Guzman, The New York Times reports.