A U.S. federal grand jury on Thursday expanded the charges against the second-in-command of Mexico's Jalisco New Generation Cartel, accusing him of methamphetamine trafficking and conspiracy to launder money.

Mexican drug kingpin Audias Flores Silva was arrested on April 27 in the western state of Nayarit in an operation by Mexican Navy special forces based on information provided by U.S. agencies. He was originally charged with trafficking cocaine and heroin in an August 2020 indictment.

The capture of Flores Silva, alias "El Jardinero" or "The Gardener," was considered a major blow to the leadership of the cartel, known by its Spanish initials CJNG. The CJNG regional commander was captured while he was hiding in a roadside ditch. Security Secretary Omar Garcia Harfuch posted video on social media appearing to show a man emerging from a hole in the ground as he is being taken into custody.

He was identified by Mexican authorities as a possible successor to leader Nemesio Oseguera Cervantes, alias "El Mencho," who was killed in February in the western state of Jalisco in an army operation.

"Jardinero believed he would assume control of the violent foreign terrorist organization CJNG following the death of El Mencho. He was wrong." DEA Administrator Terrance Cole said in a statement Thursday.

The killing of "El Mencho" led to a surge of cartel violence with a wave of attacks on businesses by cartel gunmen, vehicle burnings and road blockades that killed more than 70 people, including 25 National Guard members.

The CJNG, designated a terrorist organization by the U.S. in February along with seven other criminal groups, is considered the largest in Mexico, with a presence in 21 of its 32 states. Its operations have also expanded to several countries, including the U.S.

Flores Silva, 45, served as Oseguera Cervantes' head of security, according to Mexican authorities. He later assumed control of some of the cartel's operations in the states of Nayarit, Jalisco, Mexico and Zacatecas, overseeing drug production and trafficking, as well as the operation of clandestine laboratories. He is also linked to fuel theft and extortion. The U.S. had offered a $5 million reward for information leading to his arrest.

If convicted, he could face between 10 years and life in prison.