India toxic alcohol deaths
India: Toxic liqour kills 35 people in Mumbai Arko Datta/Reuters file photo

At least 35 people have died after consuming spurious alcohol in the western Indian city of Mumbai.

Police say the death toll is likely to increase as authorities are unsure how many more have drunk the spurious alcohol.

So far, at least 20 people have been admitted to hospitals. Most of the victims are daily wage labourers and construction workers.

The incident took place in Mumbai's Laxminagar slums in Malwani.

"More deaths have been reported from various hospitals in the past few hours. In addition to the 33 deaths, nine are still critical," said Mumbai police spokesperson Dhanajay Kulkarni.

Police have arrested three people - Raju Hanmanta Pascar, 50, Donald Robert Patel, 47, and Gautam Harte, 30 - in connection with the tragedy.

The mastermind, who goes by the nickname Akka (sister), is on the run. Akka was already arrested by investigators in relation to manufacturing and supplying bootleg alcohol in December 2014.

"They manufacture it there [in Thane] and smuggle it to Mumbai in rubber tubes. Once here, it is supplied to these illegally running shops and served in glasses or bottles," said a local government official, who is aware of the industry, according to the Indian daily The Hindu.

Devendra Fadnavis, the Chief Minister of Maharashtra of which Mumbai is the capital, has ordered an immediate probe into the incident. Problems over bootleg alcohol are common across India as locally made versions, much cheaper than regular alcohol, is the obvious choice of poor labourers. Mass deaths have been reported earlier as well.