Australia has expressed deep frustration and bitter disappointment with Laos for not pursuing 1more serious charges related to the 2024 deaths of two Australian backpackers.

A Melbourne father whose daughter died from methanol poisoning in Laos has said he is "disgusted" over the charges expected to be laid.

DFAT has told the parents of the teens who died after a mass methanol poisoning incident that Lao authorities were unlikely to lay down severe charges.