Lucknow, Feb 21 : Police in Lucknow have arrested tehsildar Padmesh Srivastava and wife for the murder of a lady constable whose body was found in a drain near the Sanjay Gandhi Post Graduate Institute of Medical Sciences here. She was missing since February 13. According to the police, Padmesh became friends with the deceased constable Ruchi Singh on Facebook five years ago. The two were in a relationship and after divorcing her husband, Ruchi had started pressurising Padmesh to marry her. The call details revealed that Ruchi had made a last call to Padmesh after which he was detained for interrogation. He admitted that he was under stress because Ruchi was blackmailing him and demanding that he marry her. He said that Ruchi was murdered in her flat and the body was thrown into the drain. CO City Abhay Pandey said that the vehicle used to throw the body has also been taken into custody by the police. /IANS