Top home department sources, who asked not to be named, said the police were likely to file a report (A-summary) in court giving reasons for dropping the charges against the two women, Shaheen Dhadha, who put up the comment, and her friend Rinu Srinivasan, who had 'liked' it.
The action against the police officer, among others, is expected after an inquiry report by Sukhwinder Singh, inspector general of police (Konkan Range), is submitted to the government on Friday, the sources said.
Chief minister Prithviraj Chavan had ordered the inquiry after the widespread anger at the arrests.
According to sources, the Thane officer had disobeyed orders from seniors who had asked him not to slap sections 295 (A) and 505 (2), which pertain to hurting religious sentiments and making statements promoting enmity.
The Thane official had apparently also contacted a senior law and order police official after arresting the girls in an attempt to garner support for his actions.