Family members of deceased complained of liquor sale in the area and said the men had consumed spurious liquor that caused their death.
However, the Bihar Police have ruled out illicit liquor angle and launched a probe to gather evidence to prove what caused their death.
Police have seized about 50 liquor bottles and arrested one trader during the raid.
The incident happened on Tuesday, when several people from Gopalganj area were taken ill after drinking hooch.
The Nitish Kumar-led Grand Secular Alliance government had banned the manufacture, trade, sale and consumption of country-made liquor since April 1, and on April 5 added foreign liquor to the list.