US authorities have indicted 23 people in Puerto Rico including American Airlines employees accused of smuggling cocaine onto passenger aircraft and distributing it across the United States, according to the Justice Department.

The four count indictment states that the defendants participated in a conspiracy to possess with intent to distribute more than 9,000 kilograms of cocaine and smuggle them aboard American Airlines flights, the department said in a statement earlier this week.

The trafficking ring started operating in around 1999 when Wilfredo Rodriquez Rosado, one of the defendants recruited and organised a group of American Airlines employees to ensure that suitcases were loaded with kilograms of cocaine and smuggled about the airline’s aircraft and transported to different cities around the US.

It is said that at least eight of those indicted were American Airlines employees.

Both Puerto Rican and agents from the US Drug Enforcement Agency and FBI teamed up to investigate and arrest those involved.

The defendants face fines of up to four million dollars and up to life in prison if found guilty.

The use of commercial airlines to carry illegal drugs in and out of the US territory of Puerto Rico created a serious threat to the US, said Attorney for the District of Puerto Rico, Rosa Emilia Rodriguez-Velez.