I have a REST service method written in C#, defined as below:
[WebGet(UriTemplate = \"/{par1}/{par2}/{par3}\")] public string ProcessGet(string par1, string
Return it as a Stream - that causes the "raw" mode to be used and WCF will not touch your response. You can find more information at http://blogs.msdn.com/b/carlosfigueira/archive/2008/04/17/wcf-raw-programming-model-web.aspx.
Stream