Branded shirts worn by arrested barons have become a trend among youth who 'want to look like the bad guys'

Mexican drug traffickers in Ralph Lauren polo shirts have become unofficial promoters of the fashion among disaffected youth, much to the distress of the authorities.

The trend came to light in August 2010 with the capture of the capo Edgar Valdez Villarreal, aka La Barbie, who was brought before the press wearing an immovable smirk and one of the shirts in green.

Jose Jorge Balderas Garza, known as El JJ and accused of shooting Paraguayan football star Salvador Cabañas in a nightclub, was detained four months later wearing the same model in blue.

La Barbie and El JJ were associated with the same schism of the Beltran Leyva cartel but at least six alleged members of other organisations have been arrested in the same garment this year. They include three Zetas, one from the Southern Pacific cartel and another from the Independent cartel of Acapulco.

Originals sell for about $150 (£90), but knock-off versions are doing a roaring trade on the streets at a tenth of that price. "The kids want to look like the bad guys," said Maria del Carmen Martinez, one Mexico City vendor.

Oscar Galicia, a research psychologist from the Iberoamericana University in the capital, puts it more formally. "There is an aspirational crisis in Mexico today in which young people have lost faith in legal means for social advancement and see the 'narcos' as figures of respect." Galicia said the traffickers copied the style from the Mexican elite who began wearing the shirts several years ago. Urban-based criminals now see themselves as part of that elite and have eschewed the old image dominated by loud open neck shirts, crocodile skin boots, and large gold chains.

Last weekend, the governor of the Pacific coast state of Sinaloa said he was "enormously worried" about the number of young people wearing the shirts. "There are people who want to be like these false idols," he said, adding that he wished they would wear clothes with the images of traditional heroes such as Emiliano Zapata.

The new cross-cartel fashion also coincides with a trend towards semi-formal hitmen uniforms ranging from identical combat gear to matching trainers.