The Australian government has updated its travel advice for Fiji to warn of methanol poisoning after four Australians were taken to hospital after drinking a cocktail at a well-known Fijian resort.
The four Australian women, aged between 18 and 56, are understood to be in critical condition in hospital on Monday morning after drinking the cocktail on Saturday afternoon at the Warwick Resort bar on Fiji's Coral Coast.
[map]They were taken to the nearby Sigatoka Hospital with "nausea, vomiting and neurological symptoms".
Two of the group were taken to the Lautoka Hospital, north of Fiji's tourist hotspot of Nadi, on Sunday because of the severity of their conditions.
The ABC understands one, a 56-year-old Australian woman, has been under constant surveillance in hospital.
Another, a 19-year-old woman, is also experiencing serious medical episodes from the suspected poisoning.
It is understood two other Australian women, a 49-year-old and an 18-year-old, are still critical but currently not as serious.
But they were also transferred to Lautoka Hospital overnight to be monitored.
Federal minister Jason Clare told ABC News Breakfast it was "terrifying news".
"We've got consular officials on the ground as well helping families. And as I understand it, Fijian officials are conducting an investigation right now. That includes a police investigation," he said.
"My message for Australians travelling overseas is just be really, really careful with whatever you consume."
Tourists in Fiji warned of risks such as drink spiking
Guests staying at the Warwick Resort have told the ABC the group was drinking pina colada cocktails by the pool on Saturday before falling ill.
The ABC has been told that some of the guests started having fits, chills and tremors that evening after drinking the cocktails.
The Australian government overnight updated its travel warning for advising tourists visiting Fiji to look for "potential risks" of "drink spiking and methanol poisoning" through consuming alcoholic drinks.
Fijian health authorities have started an investigation into the cause of the suspected poisoning and the ABC understands it has tested drinks from the resort.
However, it is not yet clear what actually caused the guests to fall ill. Fiji Police are also investigating the matter.
What is methanol poisoning?
Methanol is an odourless, colourless and flammable liquid which is almost impossible to distinguish from ethanol but highly toxic.
Methanol is used in lots of household and industrial products, like paint strippers, insecticides, inks and dyes, aerosol spray cans, and petrol.
In countries with more relaxed liquor regulations, it's illegally added to alcoholic beverages — with potentially dangerous consequences.
"It's a very, very nasty compound," says Monash University's head of forensic medicine, Professor David Ranson, recently told the ABC.
"These compounds actually attack organs of the body and actually kill cells."
A very little amount — sometimes as little as a shot — can be fatal.
Incident in Fiji comes weeks after fatal Laos poisoning
The Warwick Resort told the ABC it was still operational after the hospitalisation of its guests.
"We don't have anything to disclose because the resort is under investigation," the resort's reception said.
The resort, a well-regarded stalwart of Fiji's tourism sector, describes itself as "perfect for family holidays, weddings or honeymoon".
"Our luxury resort in the Fijian Coral Coast sets the standard for exclusive beachfront resorts in Fiji," its website says.
The ABC understands on Sunday many guests were still unaware of the incident.
A Department of Foreign Affairs and Trade spokesperson said consular assistance was being provided to two Australian families in Fiji.
Three other people, understood to be two US nationals and a Fijian, also fell ill after drinking at the bar on Saturday night and were being monitored.
The travel warning from the Australian government comes just weeks after six people, including Australians Holly Bowles and Bianca Jones, died from suspected methanol poisoning in Laos.
"There's a real terrifying sense of deja vu," Mr Clare said.
"When we wake up to hear this horrific news in Fiji, I'm sure all Australians have their heart in mouth and are hoping for the best."
Additional reporting by .