Action against caution notice for property

Hello, I bought a property in 2001 under my name and my mother's. I paid all the money for the house through my savings and a loan from HDFC. In 2010, I got a gift deed done to transfer 50% ownership from my mother to me; so I now own 100% of the house. I have one brother. My father owned a property that we sold right before we bought this house. In 2009, I settled my brother's share from the sale of my father's property in 2009 and paid him 1/3rd of the sale amount adjusted for current value of the old property. I have his signature on a stamp paper stating that. This year my brother posted a caution notice for the property that I bought against the sale/transfer of the property in the newspaper. I do not live in India and did not come to know of it until this week. This seems like a blatant scheme to prevent me from selling the house. I have a buyer and the buyer says that this needs to be settled before the transaction moves forward. Any advice: 1) On what I need to do to move forward with the transaction ? 2) What actions I can take against my brother ? This seems to amount to fraud as he has no locus standi here. Thanks