Grand Hyatt Bangkok: Victims died from cyanide poisoning

Cyanide has been found in the blood of all six people who died in a luxury hotel suite in Bangkok, say doctors after examining their bodies.

Based on the initial post-mortem examination, they say there is “no other cause” that would explain their deaths “except for cyanide”.

But further tests are being carried out to determine the “intensity” of the deadly chemical and to rule out any other toxins.

Forensic investigators had earlier found traces of cyanide on the teacups used by the victims, all of whom are of Vietnamese origin including two with dual US citizenship. Police suspect that one of the dead was behind the poisoning and was driven by crushing debt – but have not said who.

The victims’ lips and nails had turned dark purple indicating a lack of oxygen, while their internal organs turned “blood red”, which is another sign of cyanide poisoning, said Professor Kornkiat Vongpaisarnsin of the Department of Forensic Medicine at Chulalongkorn University.

Doctor Chanchai Sittipunt, the dean of the Faculty of Medicine, said they still needed to find out how much cyanide was in the blood of the deceased.

“But from what we have detected – from observation, from internal organ check, from finding cyanide in the blood during the screening test – there is no other cause that would be the factor that would cause their deaths, except for cyanide,” he told reporters.

The deceased were found by housekeepers at the Grand Hyatt Erawan hotel in the Thai capital late on Tuesday.

Investigators believe they had been dead for between 12 and 24 hours by then.

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Cyanide is a rapidly-acting, highly toxic chemical that is potentially deadly. Low levels of cyanide occur in nature and in products we eat and use. But in larger doses it is a notorious poison, and has been used as a chemical warfare agent because of its fast-acting and highly lethal properties.

It can occur as a colourless gas or liquid or in crystal form. People can be exposed to cyanide by breathing it in, absorbing it through the skin, or eating food or liquids that contain it.

When consumed in large amounts, cyanide can lead to lung injury, coma and death within seconds, according to the Centers for Disease Control and Prevention (CDC).

Even in smaller doses, cyanide is still very harmful, causing chest pain, nausea, shortness of breath and vomiting.

Cyanide can produce a “bitter almond” smell but not everyone can detect this and it doesn’t always give off an odour.

Additional reporting by BBC Thai and BBC Vietnamese’s Thuong Le