Tainted alcohol has killed 19 people in Costa Rica, where its Heath Ministry is warning against drinking at least six brands and authorities have confiscated around 30,000 bottles.

The ministry alerted on Thursday that toxic levels of methanol were discovered in samples of the brands, news outlets reported.

The ministry says the people who died included 14 men and five women between ages 32 and 72. They died in several cities around the country since early June.

RELATED: Counterfeit alcohol is a growing concern for tourists abroad

Authorities urged caution because it is unclear how much alcohol had been contaminated after the samples had tested positive for methanol adulteration. They're doing a nationwide investigation.

Methanol is a non-drinking type of alcohol used for industrial and automotive purposes, according to the U.S. National Library of Medicine. It's found in antifreeze, paint remover or thinner and copy machine and deicing fluids.

The library says some symptoms of methanol poising are blurry vision or blindness, difficulty walking or breathing, nausea and fatigue.

RELATED: Hard Rock Hotel in Dominican Republic to remove liquor dispensers from minibars

RELATED: Family, friends remember local woman found dead alongside her fiance in their Dominican Republic hotel room