On the current Internet, the routing architecture consists of intra-domain routing and inter-domain routing. For inter-domain routing an autonomous system (AS), represents the administrative network domain, which is managed by a single institution with its operational policy. ASs exchange AS reachability information with each other. Without inter-domain routing, all nodes on the Internet cannot communicate across multiple ASs. Therefore, inter-domain routing is an essential element in global Internet operation. However, due to several reasons such as miss-configuration on the routers, it often happens that one AS (say AS1) propagates the prefix that has been already assigned to another AS (say AS2) and other peers receive its routing prefix update from AS2 and inject the misconfigured AS information to their peering routers. Since the routing information associated with AS1 is overwritten by AS2, AS1 loses network reachability. This problem is known as the conflict origin AS prefix or the multiple origin AS (MOAS). We recognize that this is a severe problem which degrades the quality of Internet backbone infrastructure. We focus on this problem and propose a mechanism that can detect the conflict origin AS prefix automatically using the policy database.