MEXICO CITY (Reuters) - The son of Mexican drug kingpin Damaso Lopez Nunez has handed himself over to the U.S. Drug Enforcement Administration (DEA), said a security official from the border state of Baja California.

“What we know is that he handed himself over yesterday (Wednesday). The case is now with authorities over there,” said the official, who was not authorized to speak publicly on the matter and so declined to be identified.

Damaso Lopez Serrano, heir to Lopez Nunez, who was himself arrested by Mexican authorities in May, voluntarily surrendered to the DEA in the Mexican city of Mexicali on the border with California’s Calexico, local press reported.

The elder Lopez Nunez at the time of his arrest was believed to be fighting for control of the Sinaloa Cartel against the sons of its captured leader Joaquin “El Chapo” Guzman.