KATHMANDU, March 12 The Police Record Management Department (DPPR) has handed over the leave letter to Inspector General of Police (IGP) Dheeraj Pratap Singh with effect from March 25. DPPR has also sent letter of retirement to Additional Inspectors General of Police (AIGs) Sahakul Bahadur Thapa, Uttam Raj Subedi and Dibesh Lohani, Deputy Inspectors General of Police (DIGs) Nala Prasad Upadhyay, Masood Alam Khan and Mohan Kumar Acharya who joined the service on March 24, 1993 along with Singh. The letters were sent to all the high-ranking police officers more than a week ahead of their due retirement date.