British tourists are among those in hospital after allegedly being served alcoholic drinks poisoned with methanol in Laos.
The Foreign Commonwealth and Development Office (FCDO) confirmed they were providing consular assistance to British nationals and their families following the incident in the popular backpacking town of Vang Vieng.
Four people are currently known to have died, including an Australian teenager, an American and two Danish tourists.
Many of the victims were staying at the Nana Backpacker Hostel – with staff being told that guests had fallen ill after they failed to check out on November 13.
The FCDO said it was in contact with the local authorities regarding the British nationals affected.
Those poisoned in the incident are believed to have been served drinks tainted with methanol, which is sometimes used by disreputable bars as a cheaper alternative to ethanol, but can cause severe poisoning or death.
Addressing the potential effects of methanol poisoning, Professor Alastair Hay, Professor (Emeritus) of Environmental Toxicology at the University of Leeds, said: “The risk from methanol is twofold.
“Methanol breaks down in the body to formaldehyde and then formic acid. The formic acid upsets the acid/base balance in blood and the major consequence is initially the effect on someone’s breathing.
“There are effects on many other organs the kidney being one. The disturbance of acid/base balance and disrupted breathing will eventually affect the heart and it will stop functioning.
“Formaldehyde attacks nerves, particularly the optic nerve and blindness is a potential risk.
“Depending on the severity of poisoning, treatment may require dialysis to remove methanol from blood whilst at the same time keeping someone mildly drunk by administering ethanol.
“If the poisoning is not too severe, and only blood tests will determine this, ethanol alone may suffice.”
Australian Prime Minister Anthony Albanese told parliament that 19-year-old Bianca Jones died after being evacuated from Vang Vieng for treatment in a Thai hospital.
Her friend Holly Bowles, also 19, remains in hospital in Thailand.
Australia said “several foreign nationals” had also been victims of methanol poisoning.
The US State Department confirmed that an American had died and Denmark’s Foreign Ministry said two of its citizens also died in “the incident in Laos” but neither would comment directly on a link to the methanol poisoning that killed Ms Jones.
Thai authorities confirmed Ms Jones died because of a “brain swelling due to high levels of methanol found in her system”.
Landlocked Laos is one of south-east Asia’s poorest nations and a popular tourist destination.
Vang Vieng is particularly popular among backpackers seeking partying and adventure sports.