Until now, all the smuggling vessels seized on the high seas or at clandestine shipyards built to haul multi-ton loads of cocaine under the Pacific's surface were semi-submersibles. They typically unload off Central America and Mexico drugs destined for the United States.

Equipped with air intake and engine exhaust pipes, none of those craft were capable of fully submerging so they could evade radar and heat-seeking technology of drug-interdiction aircraft.

The camouflage-painted vessel seized by Ecuadorean police Friday appears by contrast to be capable of long-range underwater operation — a development U.S. analysts have long expected, Bergman said.

Acting on a DEA tip, the Ecuadoreans found it at a sophisticated shipyard with living quarters for at least 50 people on a jungle estuary several miles from the Colombian border, he said. It had yet to make a voyage.

Built of fiberglass and other composites, it has a conning tower, periscope and air conditioning system and measures about 9 feet high from the deck plates to the ceiling, the DEA said. Ecuadorean police told the DEA the vessel has the capacity for about 10 metric tons of cargo, a crew of five or six people and the ability to fully submerge, Bergman said.

Compared to semi-submersibles, which cost less than $1 million each to build, "this is in a new maritime drug-trafficking class of its own," Bergman said.

He said U.S. nautical engineers would be taking the submarine apart in the next few days to determine its dynamics.

The regional head of Ecuador's anti-narcotics police, Maj. Enrique Bautista, would not offer details of the sub when contacted by the AP. He referred calls to the national anti-narcotics police chief, who did not respond to messages left on his cell phone.

Bautista said the seizure was "in preliminary stages of investigation."

Bergman said one man was arrested in Friday's raid on the jungle shipyard and said it was hoped he would shed some light on how long it took to build the submarine and who engineered it.

He said authorities are still investigating who financed the sub's manufacture and which trafficking organization intended to use it.

A number of illegal armed groups operate in the area, including the leftist Revolutionary Armed Forces of Colombia, or FARC. Authorities say drug trafficking is now the movement's chief source of income.

The commander of Pacific operations for Colombia's navy, Adm. Hernando Will, told the AP on Sunday that Colombia seized 22 semi-submersibles along its coast last year but only one so far this year.

In the cat-and-mouse game that law enforcement has played for three decades with drug traffickers in Colombia - the origin of some 90 percent of the cocaine sold in the U.S. as well as heroin - the smugglers have continuously adapted to stay one step ahead of their pursuers.

The introduction of transoceanic submarines — given the major investment they represent — amounts to raising the stakes ever higher, Bergman said.

"A lot of thought, a lot of resources, went into this."