People and activists of the anti-land acquisition Bhumi Uchhed Protirodh Committee (BUPC), which was at the forefront of the agitation, demonstrated against the bail granted to him by Calcutta High Court on July 13.
Seth had been directed by the high court not to enter East Midnapore district, under which Haldia and Nandigram fall, till further orders, and to appear before the investigating officer twice a week.
The division bench comprising justices Ashim Kumar Roy and Tafiq Uddin had granted bail to the former Haldia strongman on a bond of Rs 60,000.
Seth, who was absconding, was arrested on March 17 from a Mumbai guesthouse by West Bengal CID along with two others -- former CPI(M) MLA Ashok Guria and CPI(M) district committee member Amiya Sahu.
The three were accused of abduction and murder in connection with the attack on a peace rally by BUPC on November 10, 2007 during the infamous 'recapture' of Nandigram.
The high court had directed the CID to investigate the case of six missing Trinamool Congress workers following habeas corpus petitions by their family members after Trinamool Congress came to power in West Bengal last year.