DALLAS (AP) – Federal prosecutors are preparing to present to a grand jury a case against three Texas men linked to a gun used in a U.S. agent’s death in Mexico.

Ranferi Osorio is accused of starting a black-market gun-smuggling business that served Mexico’s violent Zetas drug cartel. The ex- Marine veteran of the Iraq and Afghanistan wars was ordered to remain in custody at a Wednesday hearing in Dallas.

Brother Otilio Osorio and neighbor Kelvin Leon Morrison also have been ordered detained on federal weapons charges stemming from an alleged November gun-trafficking incident involving a confidential informant.

The firearms charges aren’t directly related to last month’s death of U.S. Immigration and Customs Enforcement agent Jaime Zapata in Mexico. Mexican authorities have arrested at least two Zetas members in the agent’s shooting death.

(Copyright 2011 by The Associated Press. All Rights Reserved.)

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