The Dominican Republic has cooperated but insists that it continues to be a safe destination.
"We are a model for global tourism," the country's tourism board told reporters last month. "Here we are talking about nine people, but there are countries in the area where 10 times the number of Americans have died there. But all eyes are on us."
The findings of the FBI's toxicology report are expected to be released this month.
Cases of counterfeit alcohol and 'methanol poisoning' are high on the radar of tourists, after 19 people in Costa Rica have died from tainted alcohol in the past month.
UK tourist Karin Kidd recently complained of falling ill after drinking a "soapy"-tasting Mojito at her Dominican Republic resort. The tourist from Oxford told The Sun, she was surprised "how many people were sick" during the week she was at the $360-a-night luxury resort.
Methanol is produced via illegal distillation or as an industrial byproduct. This "fake" alcohol can have a funny taste or smell.
Unscrupulous operators and organised criminals have previously used cheap, industrial alcohol to dilute drinks for profit. However this poisonous practice can result in blindness, organ failure and death.
Australian Colin Ahearn who runs a methanol awareness programme in Bali told the Herald of the risk facing tourists from methanol laced drinks.
"Methanol is a byproduct of poor distillation and can be present still if it hasn't been removed correctly through the distillation process," he said.
"It's a solvent. It takes one millilitre per kilo of body weight to kill you."
Ahearn has been an activist for methanol awareness since being deeply affected by the death of Kiwi-Australian teen Liam Davies in January 2013. He has helped campaign to publicise the dangers alongside the LIAM ( Lifesaving Initiative Against Methanol) foundation – which was set up by Davies' parents.
How to be safe
1. Methanol is only found in "fake" or illegally produced "spirits", so you can safely drink beer, wine and cider as well as premixed drinks – or any duty-free spirits you bring with you.
2. Avoid sketchy bars and clubs or those that have excessive discounts and deals. If you want to go, NEVER order cocktails.
3. Alcohol (ethanol) is not exactly an antidote, but it dilutes methanol and reduces how fast you metabolise the poison. Here's a guide from LIAM:
4. Testing alcohol by scent or by flame are neither guaranteed nor safe methods of testing so we won't outline them. You're best to avoid spirits entirely.
5. This resource by LIAM is a good one to print, bookmark and share.