In this paper we present a scheme of multi-agent argumentative negotiation in the generic domain encompassing intelligence agencies and informers. Two agents, an intelligence agency and a potential informer, negotiate multiple criteria through the sequential exchange of agreement offers and counteroffers. The goal of the negotiation phase in our work is to persuade the other party by argumentative reasons. We have studied several typical arguments, which may be useful in this context, such as ultimatums, promises of future fidelity, past behaviour, and other offerings received. Furthermore, privacy protection is one of the major issues of such negotiation of secrets with informers. This can be accomplished through the exchange of arguments in counteroffer attributes and by using encryption techniques.