A former Gulf cartel leader, Osiel Cardenas, of Matamoros, is back in Mexico after serving 14 years in United States custody, according to a tweet from Homeland Security Investigations San Antonio.

HSI said now that Cardenas has served his prison time in the U.S., he will face drug charges in Mexico. He is being held in a maximum security prison near Mexico City.

This is the result of a criminal investigation by Homeland Security Investigations - Rio Grande Valley and local law enforcement.