Portions of an unauthorised under-construction building erected in the East Kolkata Wetlands, in the interiors of Mukundapur, off EM Bypass, were pulled down on Thursday.

Civic officials said they executed a high court order that declared the three-storey building illegal and instructed the South 24-Parganas district officials to pull it down.

A group of government officials along with police went to execute the court order along with a bulldozer on Thursday.

The machine ripped off portions of the first and second floors.

The building encroaches on the East Kolkata Wetlands, an official said.

East Kolkata Wetlands is a Ramsar-recognised area spread over 125sqkm and no construction is permitted inside the area. The area is considered critical since it acts both as the lungs and kidneys of Calcutta.

“Calcutta High Court had instructed the district magistrate (South 24-Parganas) to carry out the demolition. The DM’s office passed the order to the SDO (sub-divisional officer) and then it was passed to the BDO (block development officer). Today, we are here to execute the court order,” said Mita Naskar, pradhan, Kheyadaha II Gram Panchayat.

Sources said such instances of grabbing wetlands by filling water bodies and erecting buildings are not uncommon in this part of the city.

An official of the local gram panchayat said: “We act if there is a complaint”.