A method for detecting misbehaviour of a peer node within a P2P network is proposed. The method comprises the step to choose a peer node from that network to act as a tester peer. Such a fester peer sends then a testing request message, that testing request message having as target the fester peer itself. The tester peer analyses the behaviour of the P2P network by collecting any possible response message rebted to the testing request message. The tester peer identifies any possible discrepancy with properties governed according to the predefined rules of the P2P network, in case a misbehaviour is found while being unable to identify the misbehaving peer node then a different peer node from the P2P network is chosen to act as a new tester peer till a misbehaving peer couid be identified, or all the peer nodes were tested. Sn the case a misbehaving peer node is identified then latter is isolated from the P2P network.