Three persons were arrested early on Wednesday on charges of abetting the suicide of Satyajit Banerjee, the vice-chairman of the Trinamool Congress-run North Barrackpore Municipality, police said.

Banerjee, 66, was found hanging in the bedroom of his rented accommodation in Barrackpore's Anandamath area on Saturday morning.

The police found a two-and-half-page note in his room where he had mentioned that a few persons had extorted large sums of money from him using a video clip to blackmail him, a senior officer of the Barrackpore Police Commissionerate said.

Banerjee's son Sarthak said the suicide note had named four persons.

"They used to put pressure on him and extort money. I have heard conversations where they had threatened my father that they would release the video clip on the internet and messaging apps like WhatsApp and Telegram," Sarthak said on Wednesday.

The police have identified the arrested persons as Jayshree Das, 39, Subhajit Biswas, 45, and Shukla Biswas, 34.

While Das was arrested in Raidighi, near Diamond Harbour in South 24-Parganas, Subhajit and Shukla were rounded up from Barrackpore's Titagarh, the police said.

Sarthak said his father remained untraceable after leaving home early on Friday. He said his father's phone was switched off throughout the day and the family failed to contact or locate him.

They alerted the police that Banerjee could not be traced.

A senior officer of the Barrackpore commissionerate said they had formed a special investigation team to investigate the case.