A fifth Belarusian national has died in Russia's northwestern region of Karelia after consuming bootleg vodka.
A total of eight men were hospitalized on August 22 with symptoms of poisoning after they drank a surrogate alcoholic beverage. Four died earlier this week during their hospitalization, while three others remain in serious condition.
Karelia's Health Ministry said on August 25 that lab tests revealed the presence of methanol in the victims' blood.
Methanol can be fatal if consumed. There have been many cases in Russia in recent years in which methanol was found in surrogate beverages instead of ethyl alcohol.
The Investigative Committee said earlier that it had launched a probe into the poisoning incident.
Poisonings with surrogate alcohol are common in Russia as people look to save money on cheaper drinks.
In December 2016, 78 people died in and around the Siberian city of Irkutsk after drinking a scented herbal bath lotion that contained methanol.