The FBI has launched an investigation into the death of a passenger on the Carnival Horizon cruise ship, a type of case that former FBI special agent Nicole Parker describes as “very complex.” She explained the situation to Fox News Digital, noting the intricate nature of such investigations.

Parker elaborated that the FBI often takes charge of investigations involving potential crimes on cruise ships when they occur in international waters. “The FBI is tasked with handling cases that arise in international waters,” Parker stated. “This complexity is governed by special maritime jurisdiction laws. For instance, if a ship sets sail from Miami, the Miami FBI has jurisdiction if the cruise departs or returns to a U.S. port. Should a crime happen in international waters, the responsibility lies with the FBI.”

In a statement to Fox News Digital, Carnival Cruise Line confirmed its collaboration with federal authorities after a passenger’s death on the ship’s recent journey. The Carnival Horizon successfully returned to Miami on Saturday morning as planned, according to the cruise line.

The Carnival Horizon was seen moored at the cruise terminal in PortMiami, Miami, Florida, on Sunday, December 17, 2023. (Eva Marie Uzcategui/Bloomberg via Getty Images)

The Carnival Horizon cruise ship docked at the cruise terminal at PortMiami in Miami, Florida, US, on Sunday, Dec. 17, 2023. (Eva Marie Uzcategui/Bloomberg via Getty Images)

“The death of a guest traveling on the Carnival Horizon voyage that returned on Saturday morning, Nov. 8, is being investigated by the FBI,” the company said in a statement. “Since this is an ongoing matter under the jurisdiction of law enforcement, it is up to the FBI’s Miami public affairs office to provide further details. Our focus is on supporting the family of our guest.”

The passenger has not been publicly identified, and authorities have not released any information about the circumstances surrounding the death.

An FBI spokesperson confirmed agents responded when the ship docked over the weekend and that the investigation remains ongoing.

Federal investigators are probing a death on Carnival Horizon’s recent voyage, as the cruise line cooperates with the FBI’s ongoing maritime investigation. (Getty Images)

“I can confirm that the FBI has responded to the scene,” the spokesperson told Fox News Digital. “Because this is an ongoing matter, no further information is available at this time.”

The FBI did not say what led to the investigation or whether foul play is suspected.

Parker, who spent years investigating maritime cases, said such probes often require complex coordination between agencies and cruise line officials.

A passenger died on Carnival Cruise Line’s Horizon ship. (Jeffrey Greenberg/Universal Images Group via Getty Images)

“Basically, Obama signed this law and if there are certain crimes or allegations that occur on cruise ships, then the FBI has jurisdiction to work them,” Parker added.

“I actually discuss this in my book — crimes on the high seas were part of my responsibilities at the Bureau,” she said. “It was a lot of work. I was the only one doing it, but those cases covered multiple things — probably eight or nine different categories. The FBI has the first right of refusal for those incidents, so the cruise line security officers would call me at all hours of the night, and I’d have to listen and determine whether we’d take the case.”

Stepheny Price covers crime, including missing persons, homicides and migrant crime. Send story tips to stepheny.price@fox.com.