One of Mexico's most powerful criminal gangs allegedly lured new recruits into its ranks by handing out flyers promising jobs with rapid career advancement, benefits, and a Christmas bonus in a fake private security firm fronted by a US citizen.

Eduardo Almaguer, attorney general in the western state of Jalisco, said on Wednesday that state police discovered the scheme run by the Jalisco New Generation Cartel after arresting 13 suspected members of the group last weekend.

Almaguer said the cartel had set up a security firm called Segmex that it used for recruitment in Puerto Vallarta, a popular Pacific coast resort, and in Tlaquepaque, a working-class district within the state capital, Guadalajara.

"These criminals hand out these flyers on the streets to recruit people and incorporate them into the ranks of organized crime," Almaguer said at a press conference as he held up one of the flyers used to advertise a position as a bodyguard at Segmex.

The flyer said that applicants should be able to handle firearms, have basic knowledge of self-defense, and show "initiative and a desire to better themselves." It said new recruits would receive an initial weekly salary of 3,000 pesos (approximately $170 dollars), plus benefits, although former soldiers or police officers would be offered a higher wage.

A Facebook page included in the flyer, which boasted that it was a "leader in private security," had 36 likes at the time of publication but had not been updated since last November.

Almaguer said the investigation found that new recruits were taken to a remote location where they were given a week of firearms training using paintball guns. After that, he said, they were then put to work selling drugs in Lagos de Moreno, a town in the highlands of Jalisco that has been badly afflicted by violent crime in recent years.

Recruitment was allegedly led by Johanna Mary Hernández, a 28-year-old US citizen who lived in Puerto Vallarta, and was among those arrested.

The recruits included people who previously made a living washing windscreens at crossroads or working as informal parking attendants. The investigation found that at least some of them were "tricked" and then "threatened" into working for the cartel.

The investigation began, Almaguer said, after one of the recruits who had previously worked for a security firm realized what was going on and was held for ransom when he asked to leave. He was freed, and the arrests made, after his family anonymously reported the kidnapping upon receiving a demand for one million pesos ($56,500 dollars).

The Jalisco New Generation Cartel — which has dominated criminal activity in the region over the last five years and is believed to have been involved in the fatal shootings of five police officers in recent weeks — is not the only criminal group linked to private security firms in the state.

In 2013 the US Treasury Department sanctioned Sistemas Elite, a Guadalajara-based security firm with over 150 employees. The US government said the firm was owned by Arnoldo Villa Sánchez, who it described as the chief of security for Héctor Beltrán Leyva, then the leader of the Beltrán Leyva drug trafficking organization.

A private security professional from Guadalajara, who asked that his name be withheld out of concern for his safety, told VICE News it is "very common" for criminal gangs to use private security firms to mask their illegal activity.

There is ample regulation of the industry, he said, but the authorities "do not have the disposition and the manpower to enforce the regulation."

The licenses granted by Mexico's state and federal authorities for security personnel to use firearms are commonly cloned and misused, he noted, while many security firms simply operate without official permission.

The source added that he was not surprised that the Jalisco New Generation Cartel was targeting former police officers.

"Police officers who are fired for failing vetting tests often end up working for the bad guys," he said. "The problem is that there's no follow-up process, no one knows where they go or what they do. If they've been police officers for 10 or 20 years they don't know how to do anything else, so when they're fired it's very easy for organized crime to co-opt them."

The increase in drug-related violence in the last decade has coincided with a boom in Mexico's private security industry. The professional consulted by VICE News estimates that there are well over 100 security firms operating in Jalisco alone.

He believes the situation that Mexico is currently experiencing is similar to what has happened in Brazil and Colombia, where efforts to break up large gangs caused them to fragment into smaller cells, creating more chaotic criminal landscapes.

"They capture the leaders but they leave all the guys below them loose so they band together into small groups and begin to commit high-impact crimes like theft, extortion, and kidnappings," he said. "Private security firms spring up due to the government's inability to keep their citizens safe."

However the allegations about Segmex in Jalisco suggest that private security is not necessarily any cleaner, or more effective, than the police.