Three Delta Air Lines employees have been indicted by a federal grand jury on charges they tried to smuggle more than $600,000 worth of drugs through Hartsfield-Jackson International Airport.

Luis Marroquin, 35, of Atlanta, Carlos R. Springer, 41, of Hampton and Kelvin Rondon, 27, of Atlanta were indicted this week on charges of conspiracy to possess with the intent to distribute methamphetamine and heroin. Springer and Rondon were arrested Tuesday and Wednesday, while Marroquin remains at large, according to a statement from the U.S. Attorney's Office in Atlanta.

The three men are accused of trying to smuggle the drugs into the country via a commercial airline flight from Mexico.

U.S. Attorney Sally Quillian Yates said a Delta agent found a piece of unclaimed luggage on a baggage carousel on Jan. 13 with a tag corresponding to Flight 364 from Mexico City.

Customs and Border Protection agents inspected the luggage and found multiple packages of meth and heroin, Yates said.

Springer, the supervisor of the ramp employees who unloaded the luggage from Flight 364, was interviewed by federal agents, who searched his cellphone and found incriminating text messages between him and Marroquin, Yates said.

The charges carry a maximum sentence of life in prison and a fine of up to $10 million, the U.S. Attorney's Office said. The investigation was conducted by the U.S. Attorney's Office, Homeland Security, U.S. Immigration and Customs Enforcement and Delta Air Lines Security.

“Delta takes these matters very seriously and will continue to work with law enforcement agencies in their investigation,” the Atlanta-based airline said in a statement Thursday.

Anyone with information about Marroquin's whereabouts is asked to contact the Homeland Security tip line at 1-866-347-2423.