A 30-year-old passenger has plunged from his balcony on the world’s largest cruise ship, Allure of the Seas, in waters off Mexico.
The incident was captured by a CCTV camera and seen by another passenger.
The Mexican navy and coastguard launched a search as the ship headed to Cozumel, Mexico.
A Foreign Office spokeswoman said, “We are aware that a British national has been reported missing in Mexico.
“His family have been informed and we are providing consular assistance.”
Royal Caribbean raised the alarm after the guest failed to respond to announcements.
The ship – which can carry 5,400 passengers – had sailed from Fort Lauderdale in Florida on Sunday on a seven-night cruise.