Biswas, a popular Dalit leader, was shot dead by unidentified assailants while he was attending a Saraswati Puja programme in the Nadia district on Saturday.
Biswas represented Krishnaganj constituency in the West Bengal Assembly.
“Two accused, Kartick Mondol and Sujit Mondol, have been arrested,” a senior police officer said.
According to locals, there was several “load shedding during the programme” and they smelt a conspiracy behind the outages.
The TMC and the BJP have been engaged in a bitter war of words since the killing.
While the TMC has alleged a BJP hand behind it, the latter has blamed the murder on the TMC’s internal feud.