New York CNN  — 

The former Mexican drug trafficker greeted alleged kingpin Joaquin “El Chapo” Guzman with a nod and a smile on Thursday before revealing that the Sinaloa cartel maintained a corruption budget of more than $1 million per month.

Vicente Zambada, 43, the latest cooperating witness at Guzman’s conspiracy trial in Brooklyn, New York, federal court, shed light on the millions paid by the cartel to corrupt government officials on its way to becoming one of the world’s most significant organized crime organizations.

The son of Ismael “El Mayo” Zambada – a wanted man who allegedly heads the cartel now that Guzman is behind bars – Zambada walked into court wearing a dark prison uniform. He smiled and nodded at Guzman, who sat at the defense table wearing a dark navy blue suit and matching tie.

While testifying against his onetime mentor, Zambada repeatedly referred to Guzman, 61, in Spanish as “mi compadre,” or “my buddy.” Zambada said he has known Guzman since he was 15, and that Guzman is the godfather of his youngest son.

Zambada testified that his responsibilities with the cartel included clandestine meetings with high-ranking members of law enforcement and Mexican military officials who helped facilitate smuggling operations and assured the assignment of “friendly” officers in key regions.

For their services, the Mexican government officials collected bribes from more than $1 million set aside each month, Zambada said.

That budget did not include bonuses paid after successful drug shipments, Zambada testified.

Zambada testified there was a 2008 government offer to invest in a ship from the state-owned oil company that could be used to transport 100 tons of cocaine. The deal apparently fell through.

Zambada was arrested in Mexico in 2009 and later extradited to the United States on conspiracy and drug trafficking charges. He pleaded guilty in one federal case against him in Chicago. He has not been sentenced, but faces 10 years to life in prison and agreed to forfeit $1.37 billion. He hopes his cooperation will lead to a reduced sentence.

Guzman has pleaded not guilty to charges of international drug trafficking and conspiracy to murder rivals.

The case against Guzman is built in part on the testimony of a procession of cooperating witnesses, mostly former cartel associates already incarcerated or who have been given new identities and relocated by the US government.

Zambada’s uncle, Jesus Zambada Garcia, also known as “El Rey,” or “The King,” was one of those witnesses. He testified in November that he paid off countless Mexican officials from 1987 to 2001. Once, he told the jury, Guzman asked him to deliver $100,000 to a Mexican military general to ensure a drug shipment was delivered without interruption.

Defense lawyers have sought to portray the cooperating witnesses as unreliable snitches who have exaggerated Guzman’s role in the cartel in hope of more lenient sentences.

Zambada returns to the stand on Friday.