Encroachment

Hello, We are 34 member who have purchased 88R land in 1986. We have plotted the same as per member contributions I.e. 2R,3R.. So on.We have layout for the plotting. Also, as per land registration we have one survey nos for this 7/12 extract. In this, we had left few areas as water body or unused but physically compounded. This layout is not registered with the survey office due to unawareness.As of date 95% of members have constructed houses leggaly with demarcation and corporation permission. One of water body area next to me is taken care by me since 1996 with trees planted, but since 2012 an outside person who is local politician has purchased 2R +2R land from owners who were been fooled by the sellers. They were not aware of their plot locations. In fact, this from different survey No's. Now the politician has removed our compound wall by JCB and claimed position. He is mentioning about demarcation done by surveyors to police, whereas there has been no notice to us for demarcation. He has tried last 4 times were police had warned him with no action and we had our possession intact. This time police has instructed us to maintain statusco. In fact, as per law he is now in possession of the plot. Non of our members are ready to come to Police a he threatened all of them. Pls Pls require guidance on following : 1. How can we deal with this encroachment? 2. Can this plot layout registered with local corporation? 3. How to deal with policemem