A passenger reported missing on a cruise to the Bahamas fell overboard after a night of heavy drinking with friends, authorities said Wednesday as Coast Guard crews suspended their search for the man.

Daniel DiPiero, 21, of Canfield, Ohio, is shown in a screengrab from ABC News video. His friends told authorities that they last saw him on the Mariner of the Seas cruise ship May 14. [ABC News]

Friends of Daniel DiPiero, 21, of Canfield, Ohio, last saw him on the Mariner of the Seas around midnight Sunday, Petty Officer Dana Warr said.

About two hours later, shipboard security cameras show DiPiero falling overboard from a rail near the front of the ship, investigators said.

He was reported missing Monday morning when his friends realized he had not slept in the cabin they shared. Royal Caribbean International notified the Coast Guard after searching the ship and Coco Cay, an island owned by the cruise line.

Vessels and aircraft from the U.S. and Bahamian Coast Guards searched 900 square miles of ocean between Grand Bahama Island and Coco Cay. The ship had departed from Port Canaveral.

Investigators from the FBI and the Coast Guard interviewed DiPiero's companions, other travelers and crew members Wednesday aboard the ship, the company said.

They found that DiPiero and his friends concealed liquor in mouthwash bottles and brought a bottle of rum in their luggage. The friends videotaped themselves drinking the alcohol Sunday afternoon, and DiPiero continued drinking until midnight, investigators said.

"Our thoughts and prayers remain with the young man's family and friends during this difficult time," company spokesman Michael Sheehan said.