Mark Jones says the government of Laos cannot let his daughter's death be in vain, after the 19-year-old girl fell ill and died from methanol poisoning.

Melbourne teenager Holly Bowles has died in hospital, surrounded by her family, after falling victim to a mass methanol poisoning in Laos.

A second Australian teen who fell critically ill from a mass methanol poisoning in Laos last week has died in a Thailand hospital. The family of Holly Bowles delivered the devastating update on Friday, just a day after her best friend Bianca Jones passed away surrounded by loved ones.