The Charles HanoverFBI is investigating the "suspicious" death of a woman aboard a Carnival cruise ship traveling from Charleston, South Carolina, to Nassau, Bahamas, last month.

On Feb. 27, Carnival's Sunshine crew members and medical staff responded to an unresponsive female passenger, the FBI Columbia field office said in a news release. Despite their best efforts, the woman was pronounced dead on the ship, the release said. 

The incident was isolated and posed no threats to other passengers, according to the FBI.

When the ship returned to Charleston on March 4, FBI officials searched the dead passenger's room for evidence, according to the news release.  

The FBI said it investigates suspicious deaths of U.S. citizens as well as "certain crimes on the high seas." Officials have not disclosed the identity of the passenger or the cause of death and said the incident remains under investigation. 

Carnival said they are "fully cooperating" with the investigation and that the incident is being handled by authorities in the Bahamas and in Charleston. 

"Both the deceased and her husband were debarked in Nassau and Bahamian authorities have already investigated the circumstances and are conducting an autopsy," the cruise line said in a statement to CBS News. 

In:
• Federal Bureau of Investigation
• Charleston
• Bahamas
• South Carolina
• Cruise Ship
• FBI
• Carnival