Australian teen Bianca Jones has become the fourth tourist to have died in a suspected mass poisoning in Laos.

The 19-year-old’s family confirmed her death to the media on Thursday. Hours earlier, the US State Department told the media that an American man died in the tourist town of Vang Vieng.

Two Danish women, aged 19 and 20, also died last week in Laos, Danish authorities confirmed, declining to share more due to confidentiality concerns.

The deaths remain under police investigation, but news reports and testimonies online from other tourists suggest they may have consumed drinks laced with methanol, a deadly substance often found in bootleg alcohol.

Vang Vieng is a small, riverside town in central Laos and a hub for young Westerners backpacking across Southeast Asia. It’s home to the Banana Pancake Trail – a popular backpacking route spanning Thailand, Vietnam, Laos and Cambodia.

Jones’s friend Holly Bowles is in hospital on life support, while a British woman is also reportedly in hospital.

New Zealand’s foreign ministry told local media on Thursday that one of its citizens was also unwell from suspected methanol poisoning. And the Netherlands’ foreign affairs ministry said that a Dutch tourist was sent to the hospital but is in stable condition. It is unclear how many others have fallen ill.

Australian Prime Minister Anthony Albanese said the department of foreign affairs had confirmed Jones’s death.

“Our first thoughts in this moment are with her family and friends who are grieving a terrible and cruel loss,” Albanese said on Thursday afternoon.

“This is every parent’s very worst fear and a nightmare that no one should have to endure.”

He said he hoped Ms Bowles, who is currently at Bangkok Hospital, would recover well.

The US State Department said it was “closely monitoring” the situation with regards to the American victim, adding that it was up to local authorities to determine the cause of death.

Australian, New Zealand and UK authorities have each warned their citizens to be careful of methanol poisoning when consuming alcohol in Laos.

Nana Backpacker Hostel, where the two Australian women stayed in Vang Vieng, told the BBC that it was closed for police investigation.

The hostel’s manager told the Associated Press that the two women were among more than 100 guests who received free shots of Lao vodka from the hostel. The pair then headed out for the night, he said, adding that no other guests reported health issues.

The manager said he hoped the investigation would clear the hostel’s name, but said they have stopped giving free shots for now.

In a statement to Australian newspaper the Herald Sun, Jones’s family expressed their “deepest gratitude for the overwhelming support, love, and prayers we’ve received from across Australia”.

“We kindly ask for privacy as we navigate through our grief and begin to heal,” the statement said.

Unlike ethanol, the key component of alcoholic beverages, methanol is toxic to humans. Bootleg liquor producers sometimes add it to their drinks, however, as a cheap way to increase alcohol content.

Earlier this year, at least 57 people in India died after consuming methanol-laced liquor. Similar cases of mass poisoning have also been reported across the world, from the Philippines to Peru. It has hospitalised and even killed dozens in Indonesia over the years, but it has rarely affected tourists.