The disturbing case unfolded the night before at the five-star Grand Hyatt Erawan hotel, a popular destination for upscale tourists, celebrities, and dignitaries.

According to authorities, the six Vietnamese victims – three men and three women, two of whom also held American passports – had been dead for roughly 24 hours before a maid stumbled upon the grisly scene on Tuesday afternoon.

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Six foreigners killed in suspected poisoning in Thailand hotel

Six foreigners killed in suspected poisoning in Thailand hotel

Cyanide was discovered on glasses, a water container and in coffee shared by the victims, police revealed. Meanwhile, relatives of the deceased divulged there had been a money dispute preceding the killings.

“Someone wanted these people dead,” said Thiti Saengsawang, chief of Bangkok’s Metropolitan Police Bureau, noting the suspicious “residues” found in six of the tea cups. “But we are waiting for forensics to prove how.”

The locked hotel room, the untouched room service, and the missing seventh guest have only added to the mystery, sparking a frenzy of speculation on social media – only heightened by erroneous early reports that the six had died in a shoot-out.

Srettha was quick to address the nation as the news broke, reassuring visitors of their safety and characterising the incident as an isolated event. “There were no signs of a struggle,” Srettha earlier told a late-night press conference at the hotel in Pathum Wan district.

“Our working hypothesis is there was a seventh Vietnamese person” and the victims were poisoned, he said.

Police revealed that five rooms had been booked for a group of seven Vietnamese guests, but only six bodies were found in the fifth-floor suite – leaving one person unaccounted for and potentially a suspect.

The crime scene’s appearance has fuelled a flurry of conjecture over the motive, from business disputes to outlandish conspiracies. Weerachai Phutdhawong, an assistant professor of chemistry at Bangkok’s Kasetsart University, earlier suggested the evidence pointed to cyanide poisoning.

“The only thing that was fully consumed was the tea, and for whatever liquid substance is in the flask to kick off this fast, it must be cyanide,” Phutdhawong said.

While both Vietnamese and American travellers can visit Thailand without a visa, unconfirmed social media reports suggest one of the deceased had made multiple recent trips to Bangkok. This has only amplified worries about the reputational fallout Thailand may face from a scandal involving the mysterious deaths of foreigners on its soil.

“It is too soon for tourists to be concerned about this, in my opinion,” Chan Holland, a travel agent with Bangkok-based Canary Travel, told This Week in Asia on Wednesday.

“The majority perhaps do not hear it yet. So far, no one asked about this,” she said.

“Will this impact tourism of Thailand? Maybe to some degree, but if it is only a one-off it will not affect much because, from what I can see, it is not random. It must have been premeditated and targeted a person or groups.”

Another travel agency based in Bangkok told This Week in Asia that he had received a number of inquiries from travellers late last year following a mass shooting in Bangkok’s Siam Paragon mall in October.

“So far I have received no question about [last night’s] incident. But there were some questions in October about the gun safety. That kind of random shooting can scare tourists.”

As the investigation into the hotel deaths continues, the Thai government finds itself navigating a delicate balancing act – between courting much-needed international tourism and ensuring the safety and security of its visitors.

Additional reporting by Amy Sood, Reuters, Bloomberg and Agence France-Presse