Dutch law enforcement intercepted the communications of Mexican drug suspected drug lord and former leader of the Sinaloa Cartel Joaquín Guzmán, also known as “El Chapo,” after his IT consultant turned informant.

Between April 2011 and January 2012 U.S. authorities captured a total of 1,500 calls, many of which originated from El Chapo, after his Colombian IT specialist, Christian Rodriguez, gave the FBI the encryption keys for the suspected kingpin’s network, according to the New York Times.

Rodriguez developed the secure communications via voice over internet protocol (VoIP), using Blackberry devices for what amounted to the entire cartel’s leadership in a network only accessible to those within the network.  

The informant gave authorities access after moving the network’s servers from Canada to the Netherlands during what he told the cartel’s leaders was a routine upgrade.

In actuality, the move allowed easier wiretaps since Canada and the U.S. have stricter privacy legislation while tap requests between the Netherlands and U.S. allow authorities easier access. The operation let law enforcement hear El Chapo’s voice for the first time in many years. The revelation marked the first time prosecutors had disclosed the use of high-tech cloak-and-dagger methods.