The neighbours saw smoke billowing out of the building around 2 am and the Fire department was immediately called, said a Fire officer.

Nearly 30 fire tenders were pressed into service, said the official, adding that electrical short-circuit could have caused the blaze. It may take nearly 48 hours to douse the flames, added the official.

The warehouse, one of the many old colonial buildings on the banks of the Ganga, was used as a warehouse for inflammable articles like kerosene, gas cylinders, tyres, tubes, cotton bales and paint, added the official.

The property belongs to the Kolkata Port Trust (KoPT) and is one among their five properties — other four being Clive, Fairley, Canning and Port warehouse — that line up at the Strand Road.

“The Strand warehouse was the most important and beautiful of the warehouses. It is part of the city’s heritage,” said a senior official at KoPT.

While the police claim the building had no fire prevention mechanism in place, A Majumdar, acting-chairman, KoPT said: “Once the forensic report comes in, we will be able to ascertain the exact cause of fire. We will also order an internal inquiry. Considering that most parts of the property is on fire, if the KMC asks us to demolish any part, we will comply with their orders.”

Trinamool Congress parliamentarian Sudip Bandopadhyay, who visited the spot, blamed the “Fire department’s old infrastructure” for failing to bring the fire under control even after 12 hours.