Mexican and Colombian drug cartels are diversifying their sources of income, according to a new investigative report from Univision News. The report, “Los Nuevos Narcotesoros” (New Narcotreasures), details how illegal mining of gold and iron ore is fast becoming a profit center rivaling that of drug trafficking.

Marketplace Morning Report host David Brancaccio speaks with Gerardo Reyes, director of Univision’s investigative news unit, about the business and violence behind illegal mining.

Click on the audio player above to hear more.

Spanish speakers can learn more on Twitter via @UniNoticias.

An illegal mining site in Peru.

Univision