What to Know The massive cache of drugs could be worth $1 billion, and would be the largest ever in the region, the U.S. Attorney said.

Federal agents were seen Tuesday afternoon boarding a ship, the MSC Gayane, which was docked at the Packer Avenue Marine Terminal.

15,000 kilos of cocaine equals more than 16 tons of the illegal drug.

Shipping containers full of illegal drugs have been found and seized by federal authorities at a Philadelphia port in what federal authorities describe as the largest seizure in the region's history.

A senior law enforcement official said more than 15,500 kilos of cocaine were found in seven containers, which were found aboard a cargo ship, the MSC Gayane, that previously stopped in Colombia, Chile, Panama and the Bahamas.

Sources told NBC10 the cocaine was not meant for Philadelphia but instead for the Netherlands and France.

At least two crew members of the Gayane have been charged with trafficking, according to a complaint filed Tuesday by the U.S. Attorney's Office. Other crew members were also allegedly involved, the complaint charges.

The bust occurred at the Packer Avenue Marine Terminal Port on the Delaware River in South Philadelphia, multiple local, state and federal law enforcement sources have told NBC10.

Members of the ship's crew have been arrested and charged with federal drug trafficking charges, the U.S. Attorney for Eastern Pennsylvania said in a tweet. They allegedly pulled the drugs aboard while at sea, the complaint said.

The massive cache of drugs could have a street value of $1 billion, the U.S. Attorney's Office also tweeted. The office characterized the seizure as the largest in the Philadelphia region's history.

*BREAKING NEWS* Federal authorities have seized approximately 16.5 TONS of cocaine from a large ship at the Packer Marine Terminal in Philadelphia. This is the largest drug seizure in the history of the Eastern District of Pennsylvania. @ICEgov @CBPMidAtlantic @PhillyPolice @USCG — U.S. Attorney EDPA (@USAO_EDPA) June 18, 2019

U.S. Attorney William McSwain said the ship contained enough cocaine to "kill millions of people."

After a stop in Philadelphia, the ship was scheduled to stop at ports of call in Europe, including in France and The Netherlands.

The Gayane was built in 2018 and flies a flag of the African country of Liberia, according to shipping records. It moored in Philadelphia at 5 a.m., Monday, the records show. It remained docked in Philly Wednesday morning.

The records show that the Gayane's previous stops included Freeport, the Bahamas on June 13, Cristobal, Panama on June 9, Cristobal, Panama, on May 24 and Buenaventura, Colombia, on May 19.

MSC, which is short for Mediterranean Shipping Company, is headquartered in Europe, and has U.S. operations based in several American cities. The international company has 54 cargo ships in its fleet.

In a statement posted to its website Tuesday afternoon, MSC said the company "is aware of reports of an incident at the Port of Philadelphia in which U.S. authorities made a seizure of illicit cargo. MSC takes this matter very seriously and is grateful to the authorities for identifying any suspected abuse of its services."

"Unfortunately, shipping and logistics companies are from time to time affected by trafficking problems. MSC has a longstanding history of cooperating with U.S. federal law enforcement agencies to help disrupt illegal narcotics trafficking and works closely with U.S. Customs and Border Protection," the statement said.

A company official declined to comment beyond the statement.

Officials with Customs and Border Patrol and Immigration and Customs Enforcement of the Department of Homeland Security as well as the Drug Enforcement Administration are involved in the investigation, which one official described as "massive."

The ship's second mate, identified as Ivan Durasevic, allegedly admitted to "his role in bringing the cocaine onboard the vessel," the federal complaint said.

"Upon leaving Peru on this current voyage, he got a call from the Chief Officer to come down to the deck, at which time he saw nets on the port side stern by the ship's crane," the complaint said. "Durasevic and approximately four other individuals, some of whom were wearing ski masks, assisted in the pushing of the nets toward Hold Seven or Eight of the vessel."

He said, according to the complaint, that he was paid $50,000 by the chief officer, who has not been identified.

Another crew member, identified as Fonofaavae Tiasaga, also allegedly admitted to partaking in loading cocaine on the ship, including on a previous voyage, the complaint said.

"Prior to departing on the voyage, the ship's Electrician and the Chief Mate also approach Tiasaga and asked if he was willing to help again," the complaint states. "According to Tiasaga, each of these four crew members coordinated individual loads of cocaine."

At least twice while the ship was en route between stops in Chile and Panama, numerous smaller boats approached the Gayane at sea to hand off large bundles of cocaine, the complaint said.

None of the crew other than Durasevic and Tiasaga have been identified.

The Packer Avenue site is the largest along the Delaware River, where dockworkers unload huge container ships from overseas. Seven unloading cranes at the location owned by Holt Logistics rise along the river just south of the Walt Whitman Bridge. The shipyard has a capacity to unload 14,000 20-foot containers from cargo ships.

In March, $77 million in cocaine was seized at the Port of New York and New Jersey in what officials described at the time as the largest such bust at that port this century.

Earlier this year, a $38 million seizure took place at the Port of Philadelphia.

Gary Tuggle, the former head of DEA Philadelphia, told NBC10 there has been a resurgence of cocaine in our area.

"Cocaine is making a comeback," Tuggle said. "We're seeing a dangerous combination of lower cocaine prices, significant more demand and now more supply."