Fourteen people, including three baggage handlers for Southwest Airlines, have been charged with violating security procedures to smuggle drugs across the country from Oakland International Airport in California, according to reports citing a criminal complaint made public Monday. The scheme was reportedly in operation since 2012.

Nine of the 14 were arrested from the San Francisco area and from the state of Arkansas, the Agence France-Presse reported. Three people are still at large while two have been convicted and are serving marijuana-related prison sentences. If convicted in the latest case, each of them could face a jail term of up to 40 years and be charged a fine of nearly $5 million.

An affidavit filed by federal investigators said that the baggage handlers used their security badges to enter the airport terminal and handed over the drugs to passengers who had cleared airport security checks.

The three baggage handlers -- reportedly identified as Kenneth Fleming, 32; Keith Mayfield, 34; and Michael Videau, 28 -- relied on eight people to smuggle drugs to cities including Nashville, Phoenix, New Orleans and Little Rock, the Los Angeles Times reported, citing the complaint.

Once the weed was sold, the income from the sales were deposited into accounts managed by three people -- Ahshatae Millhouse, 27; Laticia Morris, 40; and Donald Holland II, 42, according to reports citing officials.

Kameron Davis, one of the passengers accused of accepting the contraband from the baggage handlers, reportedly made nearly $800 for each trip to Nashville carrying a total of about 30 pounds of marijuana. Davis claimed, according to the LA Times, that he would meet Fleming, turn over the package to him, and collect it back after passing through the airport's security checks.

Mayfield has also been accused of using airline cargo discounts to dispatch about two dozen shipments of at least 220 pounds of marijuana to cities including New York, Charlotte, Philadelphia, Atlanta and Dallas, the LA Times reported, citing the affidavit.