Authorities in Gujarat said on Wednesday that 38 people have died since the apparent mass poisoning on Monday.
Officials previously said 51 people were hospitalized after drinking tainted liquor in Gujarat's adjoining districts of Ahmedabad and Botad.
"They had consumed methyl alcohol, which was almost undiluted, believing it to be liquor," police official Ashok Kumar Yadav said.
Methyl alcohol is unsafe for human consumption, and is used in paint thinners, pesticides and anti-freeze products.
Sale and consumption of alcohol is banned in Gujarat, the home state of Prime Minister Narendra Modi.
Gujarat's police chief Ashish Gupta said several suspected bootleggers involved in the incident have been detained.
Illicit liquor is a huge industry in India and deaths from these illegally brewed alcohol are common. Illegal vendors have been known to add various chemicals, including pesticides and battery acid, to their product to increase the potency of the alcohol.
In 2020, nearly 140 people were killed after drinking liquor mixed with methyl alcohol in India's northern Punjab state.