How to stop an Ex parte order

We lived in a joint family with our uncle's family. The house was built in the early 2000s by my father. He used to send money to my uncle and grandfather to build the house. In 2017, my uncle moved out with his family but left his belongings behind. Despite repeated requests to collect his belongings, he made excuses and only took the important items, leaving most of the furniture. The furniture eventually rotted, and he never returned over the years.We are the legal owners of the house; it is registered in our name, and we have been paying our taxes on time. Recently, we discovered that he filed a claim in civil court, seeking a share of the house.The court initially dismissed his case, but he appealed to a higher civil court. Today, he brought an ex parte order, entered the house without informing us, and refused to leave, citing the court order. My mother and siblings protested and called the police. The police advised him to return with police protection. He is expected to come back tomorrow.Neither his name nor my grandfather's name appears on any of the property's documents. The property was solely in my father's name. We have not been made aware of the basis of the claim to his case so far and are unsure on what grounds the court issued this order. What legal actions can we take to prevent him from entering the house?