Unknown person occupying my property

There is a ongoing eviction suite with my tenant. The original tenant was Ashok Ghosh who was died and left behind his son Kausik Ghosh in the said premises and Kausik Ghosh was unheard for last 30 years presumably dead and left behind her wife Jaya Ghosh along with a son Rahul Ghosh and Payal Ghosh. Jaya Ghosh was died on 2011 and Payal Ghosh was married to abroad so Rahul Ghosh is staying in that premises. From 2012 Rahul Ghosh is not paying any rent to us so we filed a eviction suite in 2012. After that Rahul Ghosh was not seen till date and in his absence one unknown person is coming to the premises and claiming that he is the caretaker of Rahul Ghosh. So we lodged a complain In local police station but both of us My dad and that unknown Person was called in police station. As per the police he is having a paper which states that he is the caretaker so we have to allow him in the premises and when we asked about the documents police told that they can't give it to us we have to get