A head constable of Central Prison at Arthur Road has been arrested for passing a letter from gangster Harish Mandvikar to his henchman, instructing him to threaten a prime witness in a 2015 drugs case. The accused, head constable Arjun Ghodke, was sent to ATS custody till December 28.

Mandvikar has been accused of sending chits from jail to Sachin Palwekar who in turn asked Sujit Padwakar to threaten a witness in the drugs case to give testimony in favour of Sajid Electricwala, the prime accused in the case. Palwekar and Padwakar have been arrested.