How to get JSON HTTP request body from error report using elmah?

I am using Elmah to log exceptions. Elmah is great for registering request bodies if the request is a form based request (i.e. Content-Type: application / x-www-form-urlencoded), but with JSON based requests where the content type is application / json, the request body does not appear anywhere in bug reports. Does anyone know where I can find this request body so that I can diagnose my exceptions correctly?

As an explanation of what I mean by JSON based requests, here's an example of a raw HTTP request with JSON as the request body:

PUT http://mycompany.com/api/v1.0/me HTTP/1.1
Host: mycompany.com
Content-Length: 20
Content-Type: application/json

{"city":"Vancouver"}