The Royal Caribbean cruise ship Adventure of the Seas is shown docked in Aruba in this Aug. 7, 2007 photo. Credit: Dennis Matheson

Rescuers have ended their search for a 26-year-old Canadian man who went overboard on a Royal Caribbean cruise Saturday in the Caribbean.

The United States Coast Guard announced in a statement it has ended a three-day search for Tien Phuoc Nguyen, who was with his family aboard the ship Adventure of the Seas en route to San Juan, Puerto Rico when fellow passengers reported seeing him jumping overboard at 9 p.m. Saturday night.

The captain turned the vessel around and the U.S. Coast Guard launched a search that evening, but efforts to find Nguyen proved unsuccessful.

"Our thoughts and prayers are with the family and friends of this missing passenger during these difficult times," US Coast Guard Capt. Drew Pearson said in the statement.

Meanwhile, the FBI is trying to determine what caused Nyugen to go overboard.

"We are looking into whether he jumped, or whether it was an accident, or whether he committed suicide, or whether someone pushed him," Moises Quinones, public information officer for the FBI's San Juan Office, told ABC News.

READ: Coast Guard Searches for Overboard Cruise Ship Passenger

The ship's closed-circuit TV cameras caught Nyugen going overboard, according to Miami-based Royal Caribbean Cruises.

Nguyen's family is currently back home in Canada, Quinones said.

The area in which Nguyen went overboard is called the Mona Passage, a strait located between Hispaniola (Dominican Republic-Haiti) and Puerto Rico.

The Coast Guard searched more than 44 hours for Nyugen with helicopters, fixed-wing aircraft and two Coast Guard cutters.