Voice over IP is one of the fastest growing Internet based application in today's networking world. As more and more enterprises are moving towards IP based voice network, the payload security has become an important issue. The voice traffic is exposed to the same threats as the normal data traffic. However, with voice traffic, the security and accessibility requirements are different from the data traffic. While it is important to protect the voice packets from spoofing and eves dropping, it is equally important that the law enforcement agencies gain access to these voice packets when legally required. With the deployment of security mechanisms like encryption, it becomes harder for the law enforcement agencies to decipher the information hidden in the IP packets related to voice calls. It would make sense to use standardized encryption techniques with voice over IP, at the same time provide a means to decipher the data as and when needed. This would provide the law enforcement agencies an easier access to the information during critical situations provided they have access to the encryption keys. The emphasis should be placed on the choice of encryption keys making it difficult for intruders to decipher. In this paper, the authors review the security requirements of voice traffic transmitted via Internet with the law enforcement and security perspective. The authors review the requirements of various law enforcement agencies and assess the impact of security mechanisms deployed in VOIP networks on law enforcement