Kansas City, Mo. ? The words spoken in telephone conversations were automotive references such as “cars,” “motors” and “turbo,” but to law enforcement officials they meant cocaine, methamphetamine and marijuana.

Federal prosecutors on Monday charged 38 people from Kansas and Missouri with conspiracy to smuggle a massive amount of cocaine, methamphetamine and marijuana from Mexico into the United States and distribute the drugs in the Kansas City area.

U.S. Atty. Todd P. Graves said Monday the charges were filed as part of a national operation involving 135 defendants in several states and Mexico. Graves said that since 1997, a Mexican drug cartel has supplied hundreds of pounds of drugs worth millions of dollars to customers in several states, including Kansas and Missouri.

One defendant alone is alleged to have distributed cocaine worth at least $3.6 million in Missouri and Kansas, said Assistant U.S. Atty. Charles E. Ambrose.

Court records supporting the charges allege that the conspirators supplied lower-level drug dealers with methamphetamine and cocaine.

Graves said many of the conspirators operated or worked for automotive businesses such as tow services, junkyards, car washes and maintenance facilities. In an affidavit to support charges against four defendants, FBI Agent Christopher Budke contended that the conspirators often used automotive code words, such as “cars,” “motors” and “turbo,” in telephone conversations to disguise their drug references.

Investigators reviewing wiretaps of suspected dealers in California noticed conspirators there were making a large number of calls to the Kansas City area, spurring the local investigation.