The Trinamool Congress’ Birbhum strongman Anubrata Mondal issued a written apology on Friday after an audio clip purportedly featuring him hurling abuses and threatening a senior police officer in his home town Bolpur, triggered outrage.

The Trinamool Congress had set a deadline of 6pm Friday for Mondal, a former president of the party’s Birbhum unit to tender an unconditional apology or face action.

The Bengal Police has also filed a case against him.

The audio clip, which surfaced on Thursday night and quickly went viral, allegedly features Mondal, a former TMC Birbhum district president and known loyalist of Chief Minister Mamata Banerjee, threatening an unidentified police officer for favouring his political rival in the party Kajal Sheikh, and warned him with dire consequences.

The Telegraph Online could not independently verify the authenticity of the audio.

In a statement posted on X, the party said: “The party unequivocally disassociates and does not endorse the comments made by Mondal against a police officer. We strongly condemn his use of derogatory and unacceptable abusive language… failing which showcause proceedings will be initiated.”

Mondal complied, penning an apology to the officer. “I am sad about the recent incident. I can apologise to Didi’s police a hundred times,” he wrote, referring to Mamata Banerjee, who also serves as the state’s home minister.

“I cannot imagine humiliating any officer of Didi’s police.” He claimed his reaction was triggered by allegations against the officer and also raised suspicions about how the opposition BJP obtained the call recording.

“Is there any conspiracy behind this? However, if any police officer was hurt by my behaviour, I apologise,” he added.

Behind Trinamool’s washing its hands off Mondal, is believed to be a compromise between the chief minister Mamata Banerjee and the party’s general secretary Abhishek Banerjee.

For long considered a blue-eyed boy of Mamata, Mondal, has in recent months found himself out of favour. Mamata had announced in an internal meeting of the party before last year’s Lok Sabha polls, Mondal, then behind bars at Delhi’s Tihar Jail would lead the district unit once he was released.

During this month’s reshuffle in all the district organisations across the state, North Kolkata and Birbhum were kept without any district unit head. Abhishek’s disapproval of both the Kolkata North MP Sudip Bandyopadhyay and Mondal is well known.

Trinamool sources said Mamata agreed to step back from Mondal on the condition that Bandyopadhyay will be the chairperson of the Trinamool’s north, while Birbhum will be run by a nine-member committee, snatching any extra power that Mondal enjoyed.

Before his arrest in a cattle-smuggling case, Mondal, known for making controversial statements, was the last word throughout Birbhum and some parts of the district adjoining Burdwan.

Trinamool’s total control over Birbhum since the change of tide from the 2009 Lok Sabha polls was largely the handiwork of Mondal.

Earlier in the day, BJP state president and Union Minister Sukanta Majumdar shared the audio clip on X, tagging the chief minister and state DGP Rajiv Kumar, and demanded a swift investigation.

“Once one listens to this conversation, it will be amply clear how notorious criminals are being sheltered by the invincible, tall-talking CM,” Majumdar alleged.

Leader of the Opposition Suvendu Adhikari claimed Mondal also used derogatory language against women during the call.

Hours after the clip went public, a formal complaint was filed by inspector-in-charge Liton Halder of Bolpur police station, following which a criminal case was registered against Mondal.

“An FIR has been registered in Birbhum district as the IC of Bolpur police station, Liton Halder, has filed a complaint alleging that a local leader threatened him over the phone a couple of days back. The matter will be probed and strong legal action will be taken,” Birbhum Superintendent of Police Amandeep told reporters.

Mondal has been booked under multiple sections of the Bharatiya Nyaya Sanhita (BNS), including Section 222 (threatening a public servant), Section 132 (assault or criminal force against a public servant), Section 75 (sexual harassment), and Section 351 (criminal intimidation).