The Mumbai civic body on Monday began demolishing unauthorised constructions inside some flats at a posh high-rise in Prabhadevi area, officials said.The civic body initiated action at Rustomjee Crown residential tower based on complaints lodged by RTI activist Santosh Daundkar alleging unauthorised construction and alterations, amalgamation of flats, and misuse of free-of-FSI areas by converting common spaces into habitable areas.According to Daundkar’s complaint, Rustomjee Crown has two wings, A and B, with 63 floors each, while a third wing, C, is under construction and will have 65 floors. The project has three- to five-bedroom apartments ranging from 1,335 to 3,072 square feet.The tower houses apartments owned by some politicians and businessmen. Also, some foreign consulate officers and top executives are residents of the multi-storey building, as per the complaint.Daundkar alleged that some flat owners had enclosed common spaces and converted them into habitable areas measuring around 450 to 800 square feet. He claimed that, as per the prevailing market rates, the value of the allegedly illegally enclosed spaces was around Rs 2.25 crore to Rs 2.50 crore.In a communication to Daundkar in March 2026, the BMC said it had already issued 128 notices under Section 354A of the Mumbai Municipal Corporation Act and Section 53(1) of the Maharashtra Regional and Town Planning Act in connection with unauthorised work at the tower.The civic body said further action would be initiated after following due process of law and in accordance with a Supreme Court judgment, referred to in its communication.Accordingly, demolition action was carried out in three flats on Monday, officials said.Despite repeated attempts, G-South ward officer Swapnaja Kshirsagar did not respond to phone calls or text messages. However, civic officials said the ward team comprising 15 labourers, 10 staff and officers carried out demolition under police security in three flats on the first day, and the drive would continue over the next few days.