WASHINGTON — American drug enforcement agents posing as money launderers secretly helped a powerful Mexican drug trafficker and his principal Colombian cocaine supplier move millions in drug proceeds around the world, as part of an effort to infiltrate and dismantle the criminal organizations wreaking havoc south of the border, according to newly obtained Mexican government documents.

The documents, part of an extradition order by the Mexican Foreign Ministry against the Colombian supplier, describe American counternarcotics agents, Mexican law enforcement officials and a Colombian informant working undercover together over several months in 2007. 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 extradition order — obtained by the Mexican magazine emeequis and shared with The New York Times — includes testimony by a Drug Enforcement Administration special agent who oversaw a covert money laundering investigation against a Colombian trafficker named Harold Mauricio Poveda-Ortega, also known as “The Rabbit.” He is accused of having sent some 150 tons of cocaine to Mexico between 2000 and 2010. Much of that cocaine, the authorities said, was destined for the United States.

Last month, The Times reported that these kinds of operations had begun in Mexico as part of the drug agency’s expanding role in that country’s fight against organized crime. The newly obtained documents provide rare details of the extent of that cooperation and the ways that it blurs the lines between fighting and facilitating crime.