The Kolkata Municipal Corporation has started pulling down the "illegal structure" on a terrace in the Park Street-Camac Street junction that was destroyed in a fire last month.

Civic officials said the construction on the terrace was illegal and the civic body had given permission to build only the ground floor and first floors of the building. The demolition began on Monday.

The ground floor of the building has the restaurant 1000 BC Once Upon a Plate. It is still in operation. A cafe on the first floor and the restopub on the terrace are closed.

"We are pulling it down for two reasons. One, it is an illegal structure. Two, the structure has turned unstable after the fire," an official of KMC's building department said on Tuesday.

Although the demolition job began on Monday there was no way to tell from the road in front. The terrace had been built like a large container and was closed from all sides.

Rajdeep Chakraborty, son of Salt Lake's mayor Krishna Chakraborty, used to run the terrace pub and the cafe till March this year when he sold his company. Rajdeep has been running the restopub since 2016.

The first floor and the terrace had The Drunch, a cafe, and Whats in D Name, a pub. Rajdeep said he was one of the owners of the two brands.

Rajdeep on Tuesday said he "had all the permissions from the authorities that were needed to run a resto-pub."

Krishna Chakraborty, mayor of the Bidhannagar Municipal Corporation, told Metro on Tuesday evening: "My son had rented the space and he sold the company that ran it. If it was an illegal structure, how would a tenant know that? The owner is responsible if a structure is illegal. Whatever is right as per law will happen".