Authorities say they believe there may be several more shipping containers with cocaine inside, ABC News reports.
An official said the ship was headed from Chile to Europe when the drugs were found in Philadelphia after authorities received a tip Monday night. The cocaine was discovered inside eight containers from a cargo ship, sources tell Action News.
According to a senior DEA official in Washington, the latest count of the seizure is at 34,341 pounds which is just over 17 tons.
The ship's course started in Chile then stopped in Peru and the Bahamas before making its way to Philadelphia. The US Attorney's Office Eastern District of Pennsylvania says the ship was then headed to Europe with a stop in Rotterdam.
The intended destination for the cocaine shipment is unclear.
U.S. Attorney William McSwain tweeted this statement: "This is one of the largest drug seizures in United States history. This amount of cocaine could kill millions - MILLIONS - of people. My Office is committed to keeping our borders secure and streets safe from deadly narcotics."
Members of the ship's crew have been arrested and federally charged.
An affidavit of probable cause obtained by Action News shows that two of the ship's crew members have admitted taking part in loading the cocaine from 14 separate boats while en route at sea.
The illicit drugs are currently being processed.
Authorities say this is the largest drug seizure in the history of the Eastern District of Pennsylvania.
Investigators are expected to hold a news conference in the coming days.
The historic bust comes amid a series of large seizures of the drug in the Northeast, including a seizure back in May of roughly 450 kilos of cocaine at the Port of Philadelphia.
Another bust at the Port of Philadelphia in March netted a total of 450 bricks of cocaine, weighing 1,185 pounds with a street value of $38 million. At the time, law enforcement officials said it was their biggest cocaine bust at the Port of Philadelphia in 21 years.
New York saw its largest cocaine bust in a quarter century in March as well with $77 million worth of the drug seized from a cargo ship in the port of New York and New Jersey.
Traffickers have been seeking out a new market for cocaine by mixing it with the powerful drug fentanyl, which is 50 times more potent than heroin and 100 times more potent than morphine. Synthetic opioids, like fentanyl have been responsible for thousands of overdose deaths a year, according to the Centers for Disease Control and Prevention.
"Cocaine, New York's nemesis of the 90s, is back-indicating traffickers push to build an emerging customer base of users mixing cocaine with fentanyl," DEA Special Agent in Charge Ray Donovan said at the time of the New York seizure. "This record-breaking seizure draws attention to this new threat and shows law enforcement's collaborative efforts in seizing illicit drugs before it gets to the streets and into users' hands."
In July of 2018, routine examinations at the Port of Philadelphia led to a big fentanyl bust. U.S. Customs and Border Protection officers seized 110 pounds of the deadly opioid, with a street value estimated at $1.7 million.
Information from ABC News was used in this story.