“All Australians will be heartbroken by the tragic passing of Holly Bowles,” Penny Wong said in a statement.

“Just yesterday, Holly lost her best friend, Bianca Jones.”

“I know tonight all Australians will be holding both families in our hearts,” the foreign minister added.

A total of six foreign tourists have now died of suspected methanol poisoning in a backpacker hotspot in northern Laos.

They were from Australia, Britain, Denmark and the US.

Many of the victims were in their teens or early twenties and fell sick after a night out in Vang Vieng.

Australian officials are now pressing Laotian authorities for a full and transparent investigation into what happened.

Alcohol tainted with methanol is suspected to be the cause of death.

Methanol is a toxic alcohol used in industrial and household products like antifreeze, photocopier fluids, de-icers, paint thinner, varnish and windshield wiper fluid.

Despite being toxic to humans, it is sometimes used in cheaply made home brew.