Four people have died and a number of others are in hospital after allegedly being served drinks laced with methanol.
According to reports, six British travellers are among those being treated in Laos, after falling ill last week.
Two Danish women in their 20s and a 56-year-old US citizen are reported to have died in what authorities fear was a mass poisoning.
On Thursday, it was confirmed an Australian woman - named as Bianca Jones, 19, from Melbourne - had become the fourth person to die.
Her friend Holly Bowles is being treated in hospital after calling for medical help at their accommodation, Nana's Backpackers Hostel.
In a statement given to the Herald Sun, Ms Jones's family said: "It is with the heaviest of hearts that we share the news that our beloved daughter and sister, Bianca Jones, has passed away.
"She was surrounded by love, and we are comforted by the knowledge that her incredible spirit touched so many lives during her time with us.
"We want to express our deepest gratitude for the overwhelming support, love, and prayers we've received from across Australia."
One of the British travellers being treated in hospital has been named as Simone White, 28, from Orpington, Kent.
According to The Times newspaper, she became ill last week in Vang Vieng - a resort popular with backpackers.
Ms White's friend, Bethany Clarke, a healthcare worker also from Orpington, posted on a Laos Backpacking Facebook group to warn other travellers.
"Urgent - please avoid all local spirits. Our group stayed in Vang Vieng and we drank free shots offered by one of the bars," she wrote.
"Just avoid them as so not worth it. Six of us who drank from the same place are in hospital currently with methanol poisoning."
New Zealand's Foreign Ministry also confirmed one of its citizens was also unwell in Laos and could be a victim of methanol poisoning.
(c) Sky News 2024: Four dead and more in hospital with methanol poisoning after drinking 'free shots' in Laos
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