Divers frantically searching in the dark for a person believed to have fallen off a Royal Caribbean cruise ship have made a tragic discovery, finding the body of a man.

Authorities spent hours searching for the man, who reportedly fell from the 10th floor of the Oasis of the Seas cruise ship while it was docked in Puerto Rico late Wednesday night.

Coast Guard spokesman Ricardo Castrodad told The Associated Press the vessel was in San Juan Bay when the event occurred.

ABC reporter Mark Reddie is on the cruise and reported the ship’s employees frantically doing roll call to try and figure out who was missing.

Divers spent more than four hours searching for the man however CBS reports his body has now been found.

The cruise ship was hosting a cruise catered to the LGBTQ+ community from Atlantis Events.

The all gay cruise advertised itself as hosting more than 5,000 men.

The cruise started in Miami, Florida on January 19 before heading south to St Maarten and on to San Juan, where the tragedy has occurred.

The ship was due to go to Labadee, a private island, next before returning to Miami on January 26.

“Atlantis is dedicated to absolute relaxation and incredible fun. Our cruises are about newness, romance, and fresh perspective,” Atlantis Events’ page reads.

“They’re about exploration and adventure, about escaping normalcy by acting spontaneously — going places you never thought you would go and doing things you never thought you could do.

“They’re about waking up next to your husband, long-time partner, or short-term fling and realising, together, that you’ve woken up in a different and fascinating port. Mostly, though, our cruises are about having the time of your life! This is the way we play.”

News.com.au has contacted Royal Caribbean for comment.