Delhi Chief Minister Arvind Kejriwal on Monday said the police should probe the relationship between BJP parliamentarian Mahesh Girri and hotelier Ramesh Kakkar, the main accused in the murder of NDMC official M.M. Khan."Mahesh Girri forwarded the letter written by hotelier Ramesh Kakkar to the Lt. Governor which asked for removal of NDMC (New Delhi Municipal Council) legal adviser M.M. Khan. The LG then forwarded the letter to the NDMC chairman on the reference of Mahesh Girri," Kejriwal told reporters here.He asked Delhi Police to arrest Girri and interrogate him about his relationship with Kakkar."Murder cases are not solved in an open debate. The police should arrest him first and interrogate him about his relationship with Kakkar. Why did he write a letter to LG on Kakkar's behalf," he wondered.He added: "Is this how criminal justice system works in the Modi government that whoever is accused of murder will sit on dharna outside my home?"Girri has been sitting on hunger strike outside Kejriwal's residence after the latter didn't appear for an open debate with him at the Constitution Club here.Girri had dared Kejriwal over the latter's allegation regarding the murder of NDMC official M.M. Khan who was shot dead in Jamia Nagar last month.