Dabholkar worked "tirelessly to stop obscurantist practices" and his progressive social activities had evoked opposition from the rightwing communal forces, the CPI(M) Politburo said in a statement.
Describing him as "one of the staunchest anti-communal intellectuals who has been leading a movement against superstition", senior CPI(M) leader Sitaram Yechury said the hand of "communal forces is being suspected".
He demanded speedy and effective investigation of this murder to bring the culprits to justice and said the Centre should share intelligence inputs with the Maharashtra government to enable it carry out a thorough probe.
Dabholkar was the editor of 'Sadhana' magazine that was devoted to propagation of progressive thought.