MEXICO CITY – One of Mexico’s most-wanted drug lords was hiding in plain sight, eating at a seafood restaurant about 10 blocks away from the centre of San Miguel de Allende, whose colonial square is a magnet for foreign residents and tourists.

Hector Beltran Leyva, the purported head of a feared drug gang allegedly run by his family, was eating at Mario’s Fresh Seafood, a simple restaurant known among expatriates for its fresh ceviche and fish filet when federal agents swooped in on Wednesday.

Beltran Leyva was dressed in casual but expensive-looking jeans and shirt, with an open, contrasting collar and no tie, the kind of informal chic that fits in at San Miguel, where Americans and Canadians flock to restore colonial homes and take classes in the arts.

About 2:30 p.m. on Wednesday, after Mexico’s late lunch rush, Mario’s was empty, except for Beltran Leyva and an associate, German Goyenechea, a businessman and local political activist, also dressed casually in cargo pants, a T-shirt and boots.

Army special operations agents detained the pair without a tussle, even though prosecutors said both carried pistols.

“It was all peaceful,” said a restaurant employee, who agreed to talk about the event only if not quoted by name because he was afraid of getting in trouble. “Everything happened so calmly that nobody realized what was going on.”

It fit in with the laid-back style that Beltran Leyva cultivated. His family-run cartel rose to fame and power in the rough northern city of Mexicali, Baja California. Beltran Leyva, 49, assumed leadership of the family cartel after his brother Arturo was killed by troops in a gunbattle in late 2009. Two other brothers are behind bars for involvement in the organization.

Under growing pressure from Mexican and U.S. authorities, the elder Beltran Leyva moved to the central state of Queretaro, which has largely avoided the country’s drug violence. Crowded with booming, high-tech industry, much of it foreign-owned,– Queretaro appears to be the perfect place for a man with large but shadowy sources of income to blend in and launder his wealth through seemingly legitimate enterprises.

“He adopted a moderate profile and transformed his lifestyle to go undetected,” said the federal criminal investigations chief, Tomas Zeron. “He maintained his (illicit) operations far from his home … avoiding calling the attention of friends, neighbours and local authorities. He left behind luxury vehicles and adopted an identity as a wealthy businessman who bought and sold properties and art works.”

Being accompanied by a political activist when he was arrested was also true to Beltran Leyva’s style: His cartel was known as the smoothest of all of Mexico’s gangs in corrupting and coopting Mexican police and politicians.

In 2005, an aide to former President Vicente Fox was arrested for allegedly passing information to Beltran Leyva, though those charges were later dropped.

Zeron said the associate, Goyenechea, “acted as the financial operator of his (Beltran Leyva’s) group,” presumably laundering drug money.

Goyenechea has been listed as a member of a nonpartisan civic group known as Mexican Civic Parliament and Mexico’s Green Party. When contacted by telephone, both groups promised to send a statement regarding Goyenechea, but neither did.

The Beltran Leyva organization had spread to southern Mexico in the 2000s, terrorizing the resort of Acapulco and Morelos state south of Mexico City, although the violence waned somewhat after the brothers’ arrests and killing. The U.S. Drug Enforcement Administration said the leader’s arrest Wednesday brought the cartel further to its knees.

“One of the world’s biggest drug empires continues to crumble with the capture of Hector Beltran-Leyva in Mexico,” DEA Administrator Michele Leonhart said in a statement Thursday. “Much of the violence and lawlessness that has plagued Mexico can be traced to this criminal regime. ”

“Beltran-Leyva’s organization smuggled countless amounts of lethal and highly addictive drugs into the United States and other parts of the world, facilitating addiction, violence, and death,” Leonhart wrote. He added that the “DEA congratulates the Government of Mexico and the brave individuals who carried out this operation and we pledge our continued commitment to the relentless pursuit of global drug traffickers.”

At least nine capos have been killed or captured by security forces since 2009, including the arrest last February of elusive Sinaloa cartel boss Joaquin “El Chapo” Guzman, who had been among the world’s most wanted men.

According to the U.S. State Department, Beltran Leyva, alias “The H” and “The Engineer,” was born Feb. 16, 1965, in the northern Mexican state of Sinaloa, a cradle of drug trafficking.

He has been indicted in courts in the U.S. District of Columbia and New York. U.S. authorities offered a reward of up to $5 million for information leading to his capture, and Mexico put up its own bounty of 30 million pesos, about $3.7 million.

Andrew Selee, a Mexico expert at the Wilson Center think-tank in Washington, said the cartel established a pattern of extreme brutality that has become the hallmark of other gangs such as the Zetas.

“It’s a huge deal to get Hector Beltran Leyva, who took over the most bloodthirsty cartel in Mexico. The Beltran Leyva organization was known for corrupting the upper ranks of government and terrorizing communities,” Selee said.