A former Mexican army general accused of links to organized crime was cleared of the charges and released from prison on Wednesday due to lack of evidence, Mexican officials said.
Tomas Angeles, a senior figure in former Mexican President Felipe Calderon's crackdown against drug cartels, was arrested last year on suspicion of ties to the once-powerful Beltran Leyva drug cartel.
But on Wednesday Mexico's attorney general said prosecutors had found "insufficient evidence" to back the charges and a judge ordered "absolute and immediate freedom" for Angeles.
The case had created a major headache for the Mexican army, which had been at the heart of Calderon's war on drugs.
Angeles was No. 2 in the armed forces under Calderon and helped lead the government's crackdown on drug cartels after soldiers were deployed to the streets in late 2006. He retired in 2008.
Detained in May of last year along with an active duty general, Roberto Dawe, Angeles was charged in July for alleged links to the Beltran Leyva clan, which smuggled tons of cocaine, heroin, crystal methamphetamine and marijuana across the Rio Grande.
Mexican President Enrique Pena Nieto, who took office in December, has promised to put an end to the violence that exploded under his predecessor, and has taken an estimated 70,000 lives.