Someone trespassing land registered in my name through fake sale deed

There are two open plots registered on my name, which have been recently trespassed. On obtaining the Encumberance certificate the fake entry was reflected. I filed an FIR with the police station who seem to have investigated and orally reported to me about the fake sale deed and informed me that I am the genuine owner of the open plots. Police are insisting me to construct the compound wall immediately inorder to see if any third party is coming forward to claim the same. Should I go ahead with the compound wall construction without LRS as suggested by the police. The case is still pending. When will it close and what documents will the police hand - over to me. How can the fake name from Encumberance certificate be removed. Kindly guide me in this issue. Hoping for an affirmative response. Thanks & Warm Regards.