Medical reports from Thailand have shed light on the mysterious death of two Quebec young tourists, as it is believed that Audrey Belanger, 20, and her sister Noemi Belanger, 26, died after ingesting a large quantity of insecticide in June.

The revelation -- from a Thai hospital autopsy -- confirms an earlier autopsy result suggesting a poisoning death but also leads to more questions, concerning how and why the young women would have swallowed the powerful toxin.

The dead girls’ father Carl Belanger, a shopkeeper in small-town Pohenegamook, near the Maine border, said that he would like a more thorough investigation, especially considering that other similar cases had previously been reported on the same Thai island since 2009.

One Norwegian tourist and one American tourist died under similar circumstances.

Tourists to the region occaisonally drink a potentially-lethal cocktail of cough syrup, cola, DEET and kratom to imitate what is believed to be a local custom practiced by some locals who did not drink alcohol.

-With a file from The Canadian Press