There is a “Get Messages” section for each queue in the management API. However this causes the message to be consumed and hence is a destructive action. We can re-queue this message to the queue only at the expense of sacrificing the ordering of messages [for rabbitmq versions < 2.7.0].
A more viable alternative would be to use the firehose tracer, http://www.rabbitmq.com/firehose.html [for rabbitmq versions> 2.5]. This essentially publishes the message to a different exchange (amq.rabbitmq.trace) just for debugging purposes.
Here is another GUI written on top of firehose for better visibility, http://www.rabbitmq.com/blog/2011/09/09/rabbitmq-tracing-a-ui-for-the-firehose/