Over the past year, seven American tourists have mysteriously died while vacationing in the Dominican Republic, and federal authorities are now weighing the possibility that poisoned alcohol may be the cause.

Officials want to know who supplied the alcoholic beverages the victims drank in the minutes and hours before their deaths over the past year — and if the drinks had any dangerous chemicals in them, law enforcement sources said.

The FBI is assisting and will take blood samples from the dead back to its research center in Quantico, Va., a source said.

The Dominican government insists the fatalities are isolated incidents, while reps for both of the resorts where victims have died — the Hard Rock Hotel & Casino and Bahia Principe — described the deaths as simple accidents.

But most of the deaths bear similarities, as they involve apparently healthy adults — at least some of whom drank from their hotel room minibar before suddenly becoming gravely sick.

Several of the deceased reportedly drank from their hotel room minibars before becoming ill.

The deaths have mostly occurred at two resorts: the Hard Rock Hotel & Casino and Luxury Bahia Principe Bouganville hotel.

Seven Americans have died in suspicious circumstances over the past year: David Harrison, 45; Robert Bell Wallace, 67, Miranda Schaup-Werner, 41; Couple Nathaniel Edward Holmes, 63, and Cynthia Day, 49; Yvette Monique Short, 51 and Leyla Cox, 53.

The most recent deaths – the latest reported on Monday – have drawn attention to earlier deaths of American tourists at the two island resorts that received no publicity at the time but some of which are now considered suspect.

Five Americans have died this year alone between April and June at the resorts, while two others were reported in June and July last year.

Many of the victims apparently suffered nausea, vomiting, and diarrhea, which is consistent with methanol poisoning. Methanol, which is infamously known as “wood alcohol,” is often a contaminant in bootleg alcohol. It is toxic, and less than 1 ounce is potentially fatal if drunk.

Methanol consumption can cause a wide range of symptoms including dizziness, coma, seizure, abdominal pain, gastrointestinal bleeding, kidney failure, and effects on the heart and respiratory system. The effects experienced will vary, depending on dose and an individual’s sensitivities to the substance.

Other tourist destinations have been hit with reports of methanol poisoning. The family of a British backpacker who died after drinking gin in Indonesia that had been mixed with methanol launched a campaign to warn travelers of the dangers of fake alcohol.

Cheznye Emmons, 23, was fatally poisoned after drinking the counterfeit gin, which she bought from a shop in a sealed bottle sporting a familiar brand while travelling in Indonesia in 2013.

. . . . The practice is common in many parts of the world. However, Indonesia has recently been singled out following a number of deaths and cases of serious illness of locals and foreigners.

Some fake alcohol on sale in Indonesia has been found to contain concentrations of methanol 44,000 times above safe levels.

Figures suggest 280 people have died from illicit alcohol poisoning since 2011 in Indonesia. Three Brits have died from methanol poisoning in the country in the last five years.

Another case involved Hannah Powell, who drank methanol-contaminated alcohol during a bar crawl with two friends in Zante, Greece, in August 2016. She initially went blind and experienced kidney damage as a result of the exposure.

“Apparently mafia gangs make it in the woods and sell it to the bars for cheap – and the bars fill up their stock with it,” Hannah explains.

“So if you’re a customer you think you’re buying a legitimate Smirnoff vodka but it’s not.

“They put it in Smirnoff bottles, real bottles, so you’ve no reason to think it’s not what it is.

“It just makes it go further for the bars. They don’t have to give you the normal quantity, they can give you much less because it’s much stronger.

Robin Bernstein, the U.S. ambassador to the Dominican Republic, confirms that the FBI is conducting toxicology analyses that may take up to a month to complete.