Demolition began at a TMC office linked to Abhishek Banerjee after authorities alleged building rule violations.
Excavators demolished the structure under heavy security as BJP workers celebrated and raised party slogans nearby.
Officials said repeated notices went unanswered before action was taken under the prescribed legal process.
Demolition work began on Saturday at a Trinamool Congress (TMC) party office linked to the party's national general secretary and MP Abhishek Banerjee in West Bengal's Amtala, with the district administration alleging that the five-storey building had been constructed without an approved building plan and in violation of building rules.
According to news agency PTI, excavators were deployed to pull down the structure amid heavy security. Personnel from the West Bengal Police and the Central Armed Police Force (CAPF) were deployed around the site, while Fire and Emergency Services personnel remained present as a precaution.
The demolition triggered celebrations among BJP workers and supporters gathered near the site, who raised slogans in support of the party.
BJP MLA from Amtala Agnishwar Naskar welcomed the action, alleging that the building had been constructed in violation of building regulations.
"The structure was built illegally, and the administration has finally acted in accordance with the law," Naskar said.
District administration officials said the action followed complaints alleging unauthorised construction. They said notices had been issued to the persons concerned, asking them to appear for a hearing as part of the statutory process.
"The administration has initiated proceedings strictly in accordance with the provisions of the law. Notices were served after complaints were received regarding the alleged unauthorised construction, and the matter is under adjudication," a senior South 24 Parganas district administration official told PTI.
"Any further action will be taken only after the hearing and in compliance with the relevant legal provisions," the official added.
Officials said additional security arrangements were made around the party office from Saturday morning, with barricades erected around the premises and senior police and civil administration officials supervising the operation.
"We have made all necessary arrangements to ensure that the proceedings are carried out peacefully and in accordance with the law. The demolition work is being undertaken strictly on the basis of the legal process," the official said.
According to notices issued by the district administration, the land on which the party office stands was allegedly purchased in the name of a company, Leaps and Bounds. The notices also sought clarification on documents relating to land ownership and records connected with the construction.
Administration sources told PTI that the authorities decided to proceed with the demolition after receiving no response to two notices issued to the persons concerned.
