A batch of home-brewed liquor - possibly laced with a lethal dose of the highly toxic chemical methanol - has killed 143 people in eastern India, officials say.

Hospitals near the impoverished district of 24-Parganas, 30km from the West Bengal state capital Kolkata, have been overwhelmed by victims.

Many of the victims were labourers and rickshaw drivers too poor to afford branded alcohol.

Bootleg liquor is widely consumed in India because of its low cost, with a local resident in the affected area telling reporters that a half-litre cost as little as €0.8.

Methanol - a type of industrial-strength alcohol used as anti-freeze or fuel - had been found in the remains of 20 of the victims examined by doctors, leading to suspicion that the chemical was to blame.

It is sometimes added to "moonshine" in small quantities to increase the alcohol content, but it can cause blindness, liver damage and, in the worst cases, death.

Four people have been arrested over the deaths, while the Chief Minister of West Bengal, Mamata Banerjee, has announced an inquiry and said the family of each victim will receive compensation.

Angry local residents ransacked village breweries and staged protests, local police said.

Johnson Edayaranmulah, executive director of the lobby group Indian Alcohol Policy Alliance, said that deaths from adulterated alcohol were common in the country.

He said that if methanol was to blame, it might have been mistaken by the producers for ethanol, which is less toxic.

Bootleg liquor is available "everywhere" in India, he said.

"Police take bribes, excise officers take bribes, everyone turns a blind eye to this. It shows the corruption that is part of the Indian mindset."