The separate notices were sent two days before a joint team of Kolkata Municipal Corporation (KMC) and police raided the party office on the two floors on Thursday and removed a billboard bearing the party's name from the top of the building.

Police arrested 13 people and registered three FIRs in connection with the incident for allegedly obstructing government officials. On Saturday, they arrested another person, Taufiq.

"He was identified from a CCTV grab for his alleged involvement in the Camac Street incident," a senior police officer said.

One of the notices was sent to Debraj Chakraborty, the arrested Trinamool leader from Rajarhat-Gopalpur, as he was the authorised signatory to the lease agreement. The other was sent to the West Bengal Trinamool Youth Congress, which was a party to the lease agreement.

"These are legal notices that say the two floors must be vacated within 24 hours of receiving the notice. The notices were sent on August 25. The letters were sent by mail and also by speed post," said Sagnika Banerjee, the advocate representing Ramadevi Goenka, the owner of the two floors that were leased out.

Banerjee said the lease agreement was struck on March 1, 2020, for a period of 10 years and added that the party took possession of the two floors almost forcibly, violating clauses of the agreement.

"We had lodged police complaints earlier alleging violation of the terms and conditions of the agreement. But there was no action," Banerjee said.

"We didn't press charges because the party was in power in the state. With the change of guard, there is hope. If the party doesn't respond, we will lodge a fresh police complaint. If it doesn't work, we will move the court."

The Camac Street building witnessed a fracas between Trinamool leaders, led by the party's general secretary Abhishek Banerjee, and police and KMC officials when some civic workers arrived with gas cutters and wanted to go to the rooftop on Thursday afternoon.

Trinamool supporters blocked the terrace stairs, allegedly preventing Shakespeare Sarani police personnel and KMC officials from entering the party office. A scuffle followed.

Trinamool Rajya Sabha MP Derek O'Brien fell on the stairs as the police and others tried to make their way upstairs.

Some police personnel were allegedly attacked, and general secretary Abhishek Banerjee went live on social media alleging police excesses.

On Saturday night, a team from Shakespeare Sarani police station reached Abhishek's Kalighat house and handed over a summons directing the Trinamool general secretary to face interrogators at the police station on September 1, around noon.

The building, which became a flashpoint Thursday afternoon, had no police presence on Saturday.

Entry to the building, which houses the I Love Haldiram store on the ground floor and some corporate offices on the remaining floors, was restricted.