My dad is being cheated in a property investment

My dad has been cheated by his friend. My dad invested 8lacs in a property in new mumbai in partnership with his friend in 2011. Out of 8Lacs , 7 Lac were in cash where as 1 lac was in cheque in favour of some ocean developers from new mumbai. He never showed property even after suggesting multiple times due to which my dad got suspicious and asked to return the money or provide details of the property. Now since then he is just fooling and not returning money by giving excuses. In proff we have 1 lac cheque given to a developer whom we never ever met or know the property for which it was paid. I have also taken a video of my dad's friend in which he confirms everything about the investment of 8 lac from my dad and also how he fools by sometime saying property rates have not increased , shall provide details of property etc etc. Now he has added my number to ignore list and also when I call from other number he picks and drops without talking much and then adding number to ignore list. Our family lives in Borivali , mumbai and till today we don't have our own flat and we live on rent where as my dad's friend has two flats of his own in posh society in borivali. His wife insults us when we go to their house...Kindly advice what can be done and are these proff enough (cheque of 1 lac + Video footage) if gone legal way. Also suggest some alternate way to recover.