The Bombay High Court, earlier this month had instructed CBI to take over the case after a PIL was filed by journalist Ketan Tirodar. For months the Mumbai police remained cluless about the accused.
Though the police officials arrested many people and interrogated them, they drew a complete blank.
Dabholkar was shot dead by two people on August 20 last year after he left his house for his morning walk. Two people on a motorcycle opened fire at him and escaped.
Dabholkar's death sparked massive protests across the country with people demanding justice for his death. Dabholkar was known to spearhead the campaign against superstition in Maharashtra.