Australia warns travellers against two Laos spirits

Noting the deaths, the Australian travel advisory said travellers should "be alert to the potential risks particularly with spirit-based drinks including cocktails".

Among those who died in Vang Vieng were two Australians, Bianca Jones and Holly Bowles who were both 19. All of them had been staying at the Nana Backpackers hostel.

Eight members of staff were detained on Tuesday, but have yet to be charged.

The owners of the hostel, which is now closed, had previously denied serving illicit alcohol.

Families of the Australian victims have urged the government in Laos to continue pursuing the case.

"I was happy to hear that there’s been some movement over in Laos - we cannot have our girls passing and this continuing to happen," Jones's father Mark told reporters earlier.

The other four victims have been named as Simone White, a 28-year-old lawyer from the UK; James Louis Hutson, a 57-year-old American; and Danish citizens Anne-Sofie Orkild Coyman, 20, and Freja Vennervald Sorensen, 21.

It is unclear how many people remain ill from the suspected poisoning in Vang Vieng.

News reports say the tourists could have drunk alcohol laced with methanol, a toxic industrial chemical.

The colourless and odourless substance is often used in bootleg alcohol, and medical experts suggest say drinking as little as 25ml of it can be fatal.

The UK's Foreign Commonwealth and Development Office has also updated its travel advice to reflect the dangers of methanol poisoning in Laos, warning that the substance has been used in the manufacture of counterfeit replicas of well-known liquor brands.