Federal investigators are looking into whether stowaways are tucked inside a shipping container aboard a vessel docked at a Newark, New Jersey, seaport.
During a routine security check, a Coast Guard boarding team heard sounds coming from inside the container, prompting the investigation, according to Coast Guard spokeswoman Lt j.g. Fannie Wilks.
"There is no way to know exactly what is inside because we have not opened it yet, but we can knock on the container and hear someone knock back," she said. "Thus it is our understanding that there is at least one person in the container."
The Cyprus-flagged cargo ship -- which maintains about 2,000 containers -- last docked in Egypt, and had made a stop in Pakistan after originating in India, officials said.
"U.S. Department of Homeland Security law enforcement officers and agents are currently investigating allegations of stowaways," said Anthony L. Bucci, a spokesman for U.S. Customs and Border Protection.
Inspectors first checked the ship around 3 a.m. Wednesday.
Just prior to docking, the inspectors tapped on the bulkhead and heard something, said Coast Guard spokesman Charles Rowe.
They "tapped twice" and got "two taps back," he said. "Tapped 3 times" and got "three taps back," Rowe added, a process done periodically over several hours as they investigated.
But inspectors haven't heard the suspicious tapping since the ship docked at 8:30 a.m. Wednesday.
The vessel -- which is named the Ville D' Aquarius and managed by Global Ship Lease Services Limited -- is not loaded with dangerous cargo, and the container in question is underneath several other containers, said Coast Guard spokeswoman Michelle Krupa.
The operating transportation company is working closely with U.S. officials as they investigate the situation, said Darrell Wilson, a spokesman for CMA-CGM, a French-based firm considered the world's third largest container shipping company.