Authorities in Mexico have uncovered a web of human trafficking alliances stretching across 17 states and involving groups from the biggest cartels down to family-run crime clans, in an illustration of the scale of the trade and the pressure on major criminal organizations to move into new businesses.

Based on testimony from victims, the Attorney General’s organized crime unit (SEIDO) linked crime families in the small central state of Tlaxcala to drug cartels including the Zetas, the Familia Michoacana, the Knights Templar and the Gulf Cartel, reported Excelsior.

One of the routes used by the networks is to bring minors from the southeast states of Oaxaca, Veracruz, Hidalgo and Chiapas and transport them by truck to safe houses in Tlaxcala, from where victims are either moved to Tijuana near the US border or to Mexico City.

The tactics used to obtain victims have reportedly developed over time, with criminal groups now often using social networking sites rather than kidnapping to recruit victims, found SEIDO.

According to Excelsior, 70,000 people become victims of human trafficking every year in Mexico. The crime earns criminal groups an estimated $42 million annually — which amounts to about $600 per victim — and 47 criminal organizations are involved.

InSight Crime Analysis

In 2010, the Coalition Against Trafficking in Women and Girls in Latin America and the Caribbean (CATW-LAC) reported that an estimated 1.2 million people in Mexico were victims of human trafficking. The National Refuge Network has reported that 800,000 adults and 20,000 children are trafficked for sexual exploitation in the country each year.

SEE ALSO: Slavery in Latin America

As highlighted by Excelsior, the human trafficking business model is sophisticated, with the work divided between a range of criminal groups responsible for different aspects of the trade, such as recruitment or transport.

Human trafficking in the country used to be dominated by small, independent networks, but drug cartels have taken an increasingly important role in the crime as they seek to diversify their revenue streams in the face of pressure on the drug business. In 2013, the regional head of CATW-LAC stated that 70 percent of sex trafficking cases reported to the organization involved drug gangs.

The importance of Tlaxcala in the human trafficking networks may be due to the state’s central location and proximity to Mexico City. Between January 2010 and July 2013, Tlaxcala saw the greatest number of convictions for human trafficking and tied with Baja California for the largest number of cases opened for this crime. The state was also the site of a major sex trafficking network dismantled in 2011.