Mexico's public enemy No. 1, Joaquin "El Chapo" Guzman, was nabbed last week after a gunfight and high speed getaway bid. But his more discreet partner is flourishing, moving tonnes of drugs to the United States and laundering the profits at home.

Ismael "El Mayo" Zambada jointly heads the powerful Sinaloa cartel and, with Guzman behind bars again and facing possible extradition to the United States, it falls to Zambada to maintain the gang's ranking as the world's largest.

In the past few years, Mexican security forces have captured or killed almost all the leading kingpins who had dominated drug trafficking over the last two decades. Guzman, the most prominent of all, was recaptured on Friday, six months after his second escape from maximum security prison.

That leaves Zambada, 68, as the most senior capo still standing.

"He is the patriarch," said Antonio Mazzitelli, the U.N. representative on drugs and crime in Mexico.

Zambada was listed as a defendant in a U.S. case as long ago as 1978, when Colombia's Pablo Escobar was just starting his trafficking career. Unlike Escobar, who was shot dead in 1993, Zambada has never been arrested and is still selling cocaine.

READ: El Chapo - Word's most notorious drug lord recaptured

Eight years ago, the U.S. Treasury Department declared a business network owned by his ex-wife and children was a money-laundering front. But most of the companies are still open.

"Zambada is very careful," said Javier Valdez, a founder of Sinaloan weekly newspaper Riodoce, describing him as a man who rarely travels and avoids big cities. "He controls the Sinaloan police, he has businesses in many sectors."

Rarely photographed, Zambada keeps away from the limelight. In Culiacan, the beating heart of Mexican drug trafficking and the centre of his power, his presence is felt everywhere, although he is rarely seen.

Children grew up drinking Santa Monica milk produced at a dairy the United States said was a front organization. Others pass through the kindergarten, aquatic park, and shopping centre owned by relatives and associates.

In the small town of Salado, rumoured to be Mayo's home turf, locals warned Reuters reporters not to pry into Zambada's life. "Don't even mention his name," an old woman selling tortillas hissed.

Zambada was born in a village nestled among low mountains called El Alamo, on the outskirts of Culiacan. Until recently he was known to arrive there to hand out money and children's' gifts at Christmas, in the style of old drug lords.

In a rare interview to Mexican news magazine Proceso in 2010, Zambada said he had come close to arrest on four occasions, crawling through ditches to flee soldiers.

On the whole, he said, he was more careful than his friend Guzman. He is also more afraid of serving time, saying that he'd rather die.