"Investigating Officer is directed to expedite the investigation," Metropolitan Magistrate Pawan Singh Rajawat said.
The order was passed after the police filed a report on the status of the probe in the FIR and said it has issued notices to chief editors of various newspapers and news channels seeking certified copies of news reports of Thackeray's speech in which he had allegedly branded Bihar natives as infiltrators in Mumbai and threatened to throw them out of the state.
The police said it has also sought details of the camera persons and reporters who had reported the matter in their newspapers and news channels and the reply to the same is awaited.
In September last year, Thackeray was booked under section 153 A (promoting enmity between different groups on ground of place of birth etc), 153 B (making imputations prejudicial to the national interest) and 505 (making statements conducing to public mischief) of the Indian Penal Code.
The FIR was lodged on court's order on a complaint filed by advocate Prem Shankar Sharma.