Undercover agents with the U.S. Drug Enforcement Administration, working with their Mexican counterparts, helped transfer millions of dollars in drug cash and even escorted a shipment of cocaine via Dallas to Spain. The covert activities were undertaken as part of an operation to infiltrate and prosecute a major Colombian-Mexican narco-trafficking organization moving cocaine from Colombia to Mexico and the United States.

The undercover operation, detailed in Mexican government documents obtained by the New York Times, first came to light via a Monday dispatch by Times reporter Ginger Thompson.

The documents "describe American counternarcotics agents, Mexican law enforcement officials and a Colombian informant working undercover together over several months in 2007," Thompson reported. "Together, they conducted numerous wire transfers of tens of thousands of dollars at a time, smuggled millions of dollars in bulk cash—and escorted at least one large shipment of cocaine from Ecuador to Dallas to Madrid."

The documents "show that in 2007 the authorities infiltrated" the operations of an accused major Colombian cocaine trafficker, named Harold Mauricio Poveda-Ortega, Thompson wrote. Poveda-Ortega, also known as the Rabbit, "was considered the principal cocaine supplier to the Mexican drug cartel leader Arturo Beltran Leyva."

Leyva was killed in 2008 in a shootout with Mexican naval forces. Poveda-Ortega was arrested in Mexico City in November 2010.

The Mexican government documents include testimony from a DEA special agent "who oversaw a covert money laundering investigation" into Poveda-Ortega, Thompson reported. The documents form part of the file supporting a Mexican Foreign Ministry extradition order for Poveda-Ortega from last May 2011.

The United States, however, has declined to indicate whether Poveda-Ortega was extradited to the United States, Thompson writes. A Justice Department spokeswoman Laura Sweeney similarly told Yahoo News Monday that the department is "not in a position to comment on the specific matter."

Story continues

The Drug Enforcement Administration defended the undercover operation in a written statement given to Thompson. "Transnational organized groups can be defeated only by transnational law enforcement cooperation," the agency wrote. "Such cooperation requires that law enforcement agencies — often from multiple countries — coordinate their activities, while at the same time always acting within their respective laws and authorities."

Former DEA agent Robert Mazur, who posed as a money launderer in a similar undercover DEA investigation targeting the banks supporting the Medellin drug cartel, said such undercover operations are necessary and legitimate. Covert drug stings are critical, he says, in lining up evidence to successfully prosecute the top command and control figures of organized crime cartels.

"This is a law enforcement technique that has been used for decades," Mazur told Yahoo News in a telephone interview Monday. "If we were to embrace the concept that these undercover money laundering operations shouldn't be conducted because in a small way, they for a brief period of time create a short term benefit for the criminal, we would be doing criminal organizations around the world the greatest favor they could get. We would be closing door to one of the most effective methods available to attack what law enforcement calls the command and control of these global organizations."

The organizations targeted in these intricate DEA stings "are not people selling dime bags of crack on the street, but people trying to create terrorists states around the world," continued Mazur (Mazur, who retired from the DEA in 1998, has recounted his experience infiltrating the BCCI bank accused of money laundering for the Colombian drug cartel, in a book, The Infiltrator.)

Mazur also disputed any comparison between the undercover DEA case exposed by the Times Monday and the recent controversy over "Fast and Furious," the Bureau of Alcohol, Tobacco and Firearms (ATF) program that allegedly put guns in the hands of Mexican drug gangs.

"I would never agree in any circumstances it's worthwhile to put 2,000 weapons in the hands of criminals," he said. "Each of these operations needs to be professionally managed and individually scrutinized. This one, from what I read, is very common place, and I don't see anything in there that disturbs me in the least."

Recent DEA undercover operations have led to the apprehension and successful prosecution of two major global arms traffickers, including the Russian-born, so-called "merchant of death" Viktor Bout, who was convicted in November on four counts of plotting to sell anti-aircraft guns and other weapons to Colombia's FARC rebels; and the Syrian-born "Prince of Marbella," Monzer al-Kassar, who was sentenced by a New York court in 2009 to 30 years in prison.

Other popular Yahoo! News stories:

Want more of our best national security stories? Visit The Envoy or connect with us on Facebook and on Twitter.

Want more politics? Visit The Ticket or connect with us on Facebook, follow us on Twitter, or add us on Tumblr. Handy with a camera? Join our Election 2012 Flickr group to submit your photos of the campaign in action.