It's a potential murder mystery that occurred at sea. A dead Ukrainian sailor was found on a ship at the Port of Houston. Now, the FBI is looking into the death.

It's a case that involves international law with lots of agencies deciding who will lead the investigation.

The FBI said the body was discovered New Year's Eve while the cargo ship was still at sea. A Ukrainian official told 39 News a suspect is in custody on the ship, which docked in Houston Wednesday.

Greg Buchai, an honorary consul of Ukraine said a fight broke out on the cargo ship on New Year's Eve; however, officials would not confirm that is the reason the sailor died.

When the cargo ship -- Alexia -- arrived in Houston, so did questions. Who was the dead sailor? How did it happen?

Everyone from the FBI to the Ukrainian government wants to know.

"It's sad anytime a situation of this sort happens," said Buchai.

Buchai said not only does the sailors' death affect the Ukrainian community across Houston, but not knowing what exactly happened to the sailor is very disturbing.

"The sailor was found dead in his bed after a fight in the evening. So the cause of death at this point in time is [still] unknown," said Buchai. "It was on New Year's Eve, and for some odd reason the details are not known. But it must have been a pretty emotional situation for something like that to occur.

The FBI is making an investigation as to whether the death was caused by another sailor.

The Harris County Institute of Forensic Sciences will conduct the autopsy. It may be the only local work done on this case because the FBI told 39 News that, "it does not appear that there's U.S. jurisdiction. It appears that the jurisdiction would lie in some foreign authority at this time. They'll be investigating the death to determine the circumstances surrounding the death, and we'll also determine where the jurisdiction would fall."

"Based on my contacts at the [Ukrainian] embassy, most likely if there's any prosecution [that takes place] -- because they're Ukrainian citizens -- it will happen in Ukraine," Buchai said. "The crew members of the ship, Alexia, are all Ukrainians and the event happened in international waters."

The cargo ship came to Houston from the Netherlands. There is no official word when it will leave the Port of Houston.

UPDATE (Jan. 7, 2011) -- The Harris County Institute of Forensic Sciences identified the body as that of Oleksandr Popov of Ukraine. The case was ruled a homicide. Officials said his cause of death was blunt head and neck trauma. No additional information was available Friday.