MIAMI -

A box containing $625,000 in gold arrived at Miami International Airport early Tuesday but disappeared about an hour and a half later, Miami-Dade police say.

An American Airlines plane arrived at Miami International Airport from Guayaquil, Ecuador, and docked at Gate D3 at 4:42 a.m. Tuesday, according to a Miami-Dade Police Department incident report. A group of employees unloaded the plane -- including the box containing the gold -- and moved it to the other side of the plane about 5:15 a.m.

A tug arrived at the plane from Gate D6, according to the report. It then drove away with the cart holding the plane's cargo at 5:22 a.m. Surveillance video showed the tug continue to D37 before it entered an alley and disappeared from the video.

The cart was found in front of Gate D19 at 6:20 a.m. but without the box containing the gold.

The report doesn't indicate who owns the gold or where it was headed. Sources told Local 10 the gold was going to NTR Metals in Doral, a refining and recycling company that deals in precious metals. The business offered no comment to Local 10 about the heist.

When asked about the incident, FBI Special Agent Michael Leverock wrote in an email: "The FBI is aware of the situation. If/when we are in a position to provide details I will follow up with you."

Anyone with information on the theft is asked to call the FBI at 305-944-9101.