A relay network is a broad class of network topology commonly used in networks, where the source and destination are interconnected by means of a some nodes. In such a network the source and destination cannot transmit to each other directly because the distance between the source and destination is greater than the transmission range of both of them, hence the demand for intermediate node(s) to relay. The problem of detecting malicious relay nodes in single source, multi-relay networks has been studied in the literature for different relaying schemes. Relay nodes in apply network coding while those in and follow the decode-and-forward protocol. The authors consider a peer-to-peer (P2P) network in which peers receive and forward a linear combination of the exogenous data packets. To check out the integrity of the received packets, a key signature vector is generated at the source node and broadcasted to all nodes where it is used to check the integrity of the received packets. In and several information theoretic algorithms for mitigating falsified data injection effects are proposed. The network modeling used in these works is composed of a single source, multiple intermediate nodes which utilize network coding. We consider a multiple access relay network where multiple sources send independent data to a single destination through multiple relays, which may interject falsified data into the network. To detect the malevolent relays and dispose (efface) data from them, trace bits are embedded in the information data at each source node.