The recent death of a Virginia woman aboard a Royal Caribbean cruise ship has been ruled "suspicious" and is being actively investigated by the FBI, a spokesmen for the agency said.

The unidentified 64-year-old passenger was discovered "unresponsive" by her husband Sunday. The door to the cabin where she was found was secured with a padlock, according to The Christian Post.

FBI officials suspect the woman died somewhere around the coast of North Carolina, according to FBI spokesman and Special Agent Rich Wolf. The married couple was traveling on six-night, seven-day trip on the Enchantment of the Seas ship that left from Baltimore March 18. The ship sailed to Port Canaveral in Florida, and then ultimately to Cococay in the Bahamas, before returning as scheduled to Baltimore Monday.

"It's a death of undetermined causes," Wolf said,according to The Baltimore Sun.

The cruise ship's security team and medical staff immediately contacted the FBI after the woman was found dead. FBI agents searched the ship Monday after arrival in Baltimore, and interviewed the ship's passengers before disembarking. Officials are now conducting an autopsy on the woman's body to find the cause and manner of death. The woman's husband is also currently being questioned by the FBI.

"The ship was working with us the whole way," Wolf said. "We met the ship Monday at 7 a.m. in Baltimore."

Rob Weinhold, a "security expert," explained to CBS what "suspicious death" designation could mean in this case. "Generally, a suspicious death is in order when there is an unexpected death or not easily explained circumstances, like no obvious signs of trauma," said Weinhold.

"At the end of the day, the crime scene needs to be preserved so that physical evidence as well as witness testimony can be used to determine exactly what happened," he added.