Five people have reportedly died of poisoning in Laos. A New Zealander who is unwell may also be a victim, the Ministry of Foreign Affairs and Trade has said.
Dr Paul Gee, an emergency specialist and toxicologist, told RNZ that unfortunately, methanol poisoning is not rare in many countries.
"It actually happens all over the world," he said.
"Methanol can get into drinks in bars because it's a by-product of backyard fermentation, so in the normal industrial production of ethanol, drinking alcohol, methanol is actually removed.
"But in this case poor production procedures or lax standards have ended up with methanol in alcohol for consumption."
Dr Gee has treated patients with methanol poisoning before.
"As we've heard with the cases recently, the worst outcome is death.
"We had a patient several years ago, a tourist who was from Bali and had been drinking and got on a plane to come to Christchurch.
"As soon as she hit Christchurch she started to feel unwell. She had racing heart, vision was starting to go, so she came up to the hospital to be treated.
"She ended up in intensive care very close to death, and has been left permanently blind, which is a very sad outcome for her."
If someone thinks they have ingested methanol, they should get help immediately, Dr Gee said.
"If you are in a foreign country you basically should be aware of where you can get help.
"But one of the first aid things that you can do is get some legitimate alcohol - so, legal alcohol without methanol - can actually stop the production of acid temporarily and buy you time until you can get to a hospital where they've got dialysis in intensive care."
Much of the time methanol is introduced as a cost-cutting measure, Dr Gee said.
"The most likely way that a tourist is likely to get methanol mixed in with their drinks is if they have a cocktail for a mixed drink in a bar in one of these countries.
"In those countries bars often substitute commercially produced alcohol for bootleg alcohol because it's cheaper."
At first, a methanol high might seem like the usual booze effect, but it can quickly turn.
"When the body ingests methanol, it initially thinks it's like ethanol, you'll feel intoxicated, perhaps slightly high, but as the body converts the methanol into an acid you'll get increasingly unwell."
