In 2014, the US sent a dummy Hellfire missile to Europe to be used in training. But once the training was over, instead of the missile being shipped back to the US, it ended up in Cuba.

Since then, the US government has been working to get it back. So far, the US has been unsuccessful. Reporters Devlin Barrett and Gordon Lubold reported on this for the Wall Street Journal.

Barrett says that the missile was first sent to Spain to be used in a NATO exercise. After the exercise was complete, it was trucked to Germany and then on to Paris. Then it was loaded onto an Air France flight to Havana, Cuba.

“And that’s when US officials realized ‘Oh, wait, we’ve just accidentally sent one of our Hellfires to Cuba,'" says Barrett.

Barrett says military equipment, like the Hellfire missile, shipped via commercial companies is clearly labelled as "sensitive export-controlled technology." In other words, the container is clearly marked as something that should be returned to the US.

“So anyone who saw this package should have known right out of the gate that this wasn’t supposed to go on any, let’s just say, additional excursions,” he says.

But it did and when it finally arrived in Cuba, Barrett says, local officials seized the cargo and the shippers alerted Lockheed Martin, the missile's manufacturer. Lockheed Martin in turn alerted the US government.

A criminal investigation is under way to determine if this was simply a series of human errors or whether it was the work of criminals or spies.

Back in 1984, the US added Cuba to the list of countries to which sending US military exports is prohibited. But American officials told Barrett it would be difficult to build a criminal case against anyone involved.

“This package ... passed through a lot of hands, more than a dozen hands, before it ended up in Cuba,” he adds.

Meanwhile, Cuba has not been responsive to requests from the US to return the missile. Barrett says US officials don't believe Cuba has have great interest in the inert missile itself. But they worry that Cuba could sell the missile's technology to other hostile countries, such as China, Russia or North Korea.

This is not the first time military gear has gone missing. One official told Barrett that there are about 1,500 instances of "mis-shipments" of export-controlled technology. It’s very similar to a lost UPS package. But this case is different.

“If you lose it to a hostile country, which in many ways Cuba is, that’s a whole different can of worms for the US government,” he says.

From PRI's The World ©2015 Public Radio International