The civic body has directed the owners to demolish the disputed portions within seven days or explain why action should not be taken under the Kolkata Municipal Corporation Act, 1980.

The notices were served under Section 400(1) of the Kolkata Municipal Corporation Act, 1980.

KMC has sought documents relating to sanctioned building plans and asked whether approval was obtained for additional construction.

It has also requested details regarding installations such as lifts and escalators.

The notices state that if the owners fail to respond satisfactorily within a week, the civic body will proceed with demolition and recover the associated costs from them.

One of the notices states that the recipients are required to remove “deviated unauthorised parts of the building” within seven days from the date of service or show cause why the structures should not be demolished.

The 17 properties include residential and organisational addresses linked to Abhishek Banerjee, his parents and his company, Leaps and Bounds Private Limited.

The properties are located in several parts of South Kolkata, including Harish Mukherjee Road, Kalighat Road, Premendra Mitra Sarani, Panditiya Road and Ustad Aamir Khan Sarani.

Earlier on Monday, Chief Minister Suvendu Adhikari said that he had asked officials to collect details of properties linked to four Trinamool Congress leaders, including Abhishek Banerjee.

Adhikari alleged that 14 properties are registered in the name of Leaps and Bounds Private Limited, with four in Abhishek Banerjee’s own name and six in his father’s name.

He also named other individuals, including Raju Naskar of Beleghata, Sona Pappu of Kasba and the son of former minister Javed Khan, while citing the number of properties allegedly linked to each.

Adhikari said that the BJP would pursue legal action against individuals accused of corruption.

Referring to recent arrests of Kolkata Police officer Shantanu Sinha Biswas and former minister Sujit Basu, he said the BJP would seek to send “all the corrupt people” to jail through legal means.

Bengal minister Dilip Ghosh said the municipality would examine the allegations of illegal construction and issue notices where required.

He said the legal validity of the structures would need to be established by the concerned parties.