Agents are directly trying to find allegations of stowaways.
A cargo vessel trusted to be transporting stowaways was seized at a New Jersey port on Wednesday after it arrived in the United States following ports in India and Egypt to pick up freight, the U.S. Coast Guard announced.
Agents informed they heard what was like humans in a container buried beneath others in the vessel's hold.
The container had not been opened hours after the vessel was stopped and was being dislocated by crane to a dock so it could be searched.
The vessel's manifest told the container was loaded onto the ship on June 7 in India and was transporting machine parts.
At least 7 ambulances waited outside Port Newark-Elizabeth Marine Terminal, where dozens of containers were transported to the dock for inspection.
The ship was identified as the Ville D'Aquarius, with information from Anthony Bucci, a spokesman for the U.S. Customs & Border Protection.
The vessel was stopped at 3 a.m. EDT (0700 GMT) at a standard checkpoint for incoming vessels, the Ambrose Anchorage below the Verrazano Bridge in New York Harbor.
The vessel sailing under Cyprus flag started its voyage in Jebel Ali, United Arab Emirates, on May 30 and made a stop in Qasim, Pakistan, on June 2.