A day after he was questioned by the Mumbai Crime Branch, the Thane cops on Friday grilled Param Bir Singh, DG-Home Guard and former city police chief, for close to 8 hours in connection with an extortion case. Earlier, a Thane court had issued a non-bailable warrant against the top cop, who called himself a law-abiding citizen.

Sources said Singh has denied all the allegations in the Thane police case on the grounds that he had no role in it as he was the chief of the force and the investigation was done by his juniors. On Thursday too, he had rejected all charges.