With drug kingpin Joaquín “El Chapo” Guzmán locked up and facing U.S. extradition, his enemies are starting to pick apart his once-mighty empire.

Mexican officials say Guzmán’s eldest son, Iván Guzmán, called “El Chapito” (Little Shorty), may have been among the half-dozen people kidnapped by gunmen early Monday from a swanky cafe in Puerto Vallarta.

Eduardo Almaguer, the attorney general in the state of Jalisco, where Puerto Vallarta is located, said in an interview Tuesday with Mexico’s Radio Formula that investigators “presume” the heir apparent to Joaquín Guzmán’s Sinaloa cartel was abducted by armed men who raided the upscale La Leche just after 1 a.m. Monday.

Almaguer said investigators were studying security camera footage and fingerprints collected at the scene to determine whether Iván Guzmán was taken. It’s unclear how the gunmen would have grabbed him without a fight, as no shots were fired in the raid. Several female companions of the victims were not taken by the kidnappers, Almaguer said.