The 19-year-old boy detained by police for posting a purportedly abusive Facebook status against Maharashtra Navnirman Sena (MNS) chief Raj Thackeray was released on Thursday morning.
The police suspect that the teenager´s account was hacked before the message was put up, said reports.
The boy, a resident of Palghar, Thane, was detained there for questioning on a complaint filed by Raj Thackeray´s party. A mob of MNS supporters reportedly surrounded the boy´s home on Wednesday and forced him to go to the police station.
The incident came on a day when a bandh call by Shiv Sena affected life at Palghar with markets and educational institutions remaining shut.
However, the police did not charge him immediately but took him to the cyber-crime cell in Thane, from where he was released and returned to his home in Palghar on Thursday.
The police ran into trouble earlier over the arrest of two women last week, also in Palghar, for objecting to the shutdown of Mumbai on the day of Shiv Sena chief Bal Thackeray´s cremation. Two Palghar cops were suspended following an inquiry into the arrests that sparked an outrage.