A UK-born billionaire has been named among the passengers on the missing tourist submarine that was visiting the sunken Titanic.

Hamish Harding, who made much of his wealth in the aviation industry, was named missing along with the others onboard after concerns were raised earlier today.

The submersible takes tourists to view the wreck of the Titanic, which sank set sail from Southampton on its maiden voyage in 1912.

Mr Harding's stepson Brian Szasz said on Facebook: "Hamish Harding my step father has gone missing on submarine thoughts and prayers.

"My stepdad Hamish Harding has gone missing on a submarine pray for a successful recovery.

"Thoughts and prayers for my stepfather Hamish Harding as his Submarine has gone missing exploring Titanic. Search and rescue mission is underway."

The message has since been deleted and replaced by another reading: "For privacy my mom asked me to delete all related posts thanks for the support."

Search and rescue mission announced after tourist submarine vanishes near Titanic wreck

A search and rescue operation was announced by the Boston Coastguard near Newfoundland.

These submarines are commonly used on tourist excursions organised by the adventure trips company OceanGate Expeditions.

Each submarine is capable of seating up to five people, meaning as many as four more could be among the missing.

These submarines can seat five people according to the company which is said to include the pilot, three paying customers and a 'content expert'.

OceanGate Expedition charges guests $250,000 (£195,270) for a place on the sought-after eight-day trip to the site where the Titanic sank.

The company's site also said that one of its trips is ongoing with two more planned in June 2024.

The site where the Titanic sank was discovered in 1985 and has been explored and excavated extensively since then.

Who is Hamish Harding after UK billionaire revealed among missing on Titanic submarine?

Hamish Harding is a UK-born billionaire who is currently based in the UAE.

He made much of his wealth in the aviation industry and is the founder of Action Group and chairman of Action Aviation.

He is known for being a thrill seeker and currently holds three Guinness World records such as the fastest circumnavigation of the Earth via both poles.