FEARS have grown for a 26-year-old British tourist who vanished after reportedly becoming trapped when a fire broke out on a boat off the coast of Thailand’s notorious “Death Island“.

A huge air and sea mission has resumed in a desperate attempt to find missing backpacker Alexandra Clarke, from South London.

Alexandra is believed to have vanished after using the toilet when the blaze erupted on the dive boat – five miles from “Death Island” Koh Taoon – on Sunday morning.

The horror blaze reportedly started from an air compressor on the wooden tourist vessel.

Cops on Monday revealed Alexandra was still missing with authorities stepping up their search efforts.

Boats, specialist divers and a helicopter have been deployed to scour the area where the wooden tourist boat went down.

The Deputy Director of the local Marine Police Division, Naval Captain Natthapol Sinphulphon, revealed divers were not able to find Alexandra on the initial attempt.

Sinphulphon said: “When the dive team entered the boat to search, they could not locate the missing tourist, and the boat sank shortly after.

“It was also getting dark, and by 8pm, the dive team was exhausted, so they contacted the Maritime Enforcement Coordination Center (MEC) for assistance.”

The director added more specialised crews were needed as the area the dive vessel sank was up to 45 meters deep.

Officials said at least 16 tourists were onboard the boat, named Davy Jones Locker, as well as two crew and four instructors from the scuba diving firm.

The other people onboard were rescued by passing boats but Alexandra is feared to have become trapped in the toilet when the blaze started.

Charges have also been filed against the boat operator and staff for negligence.

Police said a Burmese crew member, Teo, 48, is understood to have been operating an air compressor to fill diving tanks when a malfunction occurred, causing the compressor to catch fire.

The Superintendent of Koh Tao Police Station, Police Colonel Sarayut Burivachira said: “Investigators have filed charges of negligence against the boat operator and the staff responsible for controlling the oxygen filling, which led to the fire and property damage.”

Burivachira added: “They have issued a warning for safe navigation and ordered the boat owner to salvage the wreck within 15 days of receiving this notice.

“The boat is prohibited from further use until it is repaired and deemed suitable for operation.”

‘DEATH ISLAND’

Koh Tao has become one of the world’s most popular scuba diving locations but several deaths have rocked the tourist hotspot.

Dozens of young visitors have mysteriously been killed, although the actual number could be much higher, with many deaths covered up to protect the lucrative tourism industry.

The most high-profile case was the death of Hannah Witheridge and David Miller, who were bludgeoned to death on Sairee Beach in in September 2014.

Two Burmese labourers were allegedly framed for the murders in order to protect the real killer – the son of a prominent local family – and wrap the case up quickly amid unwanted international scrutiny.

Prominent Australian lawyer Ian Yarwood, who has campaigned for the two Burmese boys to be released, has made repeated calls for tourists to avoid the island due to “crime, corruption and poor health and safety”.

He added: “My heart goes out to the family and friends of Alexandra Clarke.

“I suspect the fire on her dive boat was probably avoidable or could have been suppressed with proper safety equipment and training.

“Tragically, safety standards around Koh Tao are appalling compared with those in the West. Fires on Koh Tao boats and ferries are far too common.”

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