The septuagenarian Chakraborty was arrested on June 23, 2009, a day after the central government banned the radical left-wing Communist Party of India-Maoist
He was charged with several offences including under section 20 of the Unlawful Activities (Prevention) Act, which provides punishment for being member of terrorist gang or organisation and carries a maximum punishment of life imprisonment.
"The court of city Sessions Judge Kum Kum Singha acquitted Chakraborty of all the charges. The prosecution could not substantiate the charges brought against Chakraborty, and court acquitted him," said Chakraborty's counsel S. Roy.
The verdict was cheered by Chakraborty's wife Mukta Keshi and several rights activists present at the court premises.
"I always had hoped of his release someday and that today is that day," she said.
Hailing the verdict, Association for Protection of Democratic Rights (APDR), a rights organisation demanded release of several political prisoners including pro-Maoist tribal group Peoples' Committee against Police Atrocities (PCAPA) convener Chhatradhar Mahato who are now in various West Bengal jails.
"The charges under UAPA against people like Mahato and others are false and baseless and someday the courts will declare that. The Mamata Banerjee government had declared releasing all the political prisoners who have been languishing in jails for long. We demand their unconditional release," APDR secretary Ranjit Sur said.
Chakraborty became a spokesperson of the CPI-Maoist in 2008 and was active in the Lalgarh movement. He played a crucial role in uniting urban support bases in favour of the tribal upsurge in Jangalmahal- the three Left Wing Extremism (LWE) hit districts of Bankura, Purulia and West Midnapore.
Lalgarh, 200 km west of Kolkata, in West Midnapore district, was on the boil for over two years since November 2, 2008, when a landmine exploded on the route of the convoy of then state Chief Minister Buddhadeb Bhattacharjee and Union Ministers Ram Vilas Paswan and Jitin Prasada.
Complaining of police atrocities after the blast, angry tribals egged on by the Maoists, launched an agitation against the Left Front government of the day, virtually cutting off the area from the rest of the district.
The agitators torched LF spearhead CPI-M offices, drove away its supporters and forced police to leave, thereby establishing a virtual free zone.
In June 2009, joint forces comprising central paramilitary troopers and crack teams of state police reclaimed the areas and conducted intense operations to flush out the left wing ultras.
The movement gradually died down after the widespread arrests and deaths in gunfights.