The families of teenagers Bianca Jones and Holly Bowles have been "blown away" by the support of the public after their fundraising goal was surpassed overnight.

Laos police have detained eight staff and managers of the hostel where Australians Bianca Jones and Holly Bowles were staying when they fell ill. A third Australian is also recovering from suspected poisoning.

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.