How do I empty the filter on my Hotpoint Aquarius WMA50 Washing Machine?

My Hotpoint Aquarius WMA50 Washing Machine smells as if there is a blockage somewhere. There is no filter that I can see anywhere on the machine and the smell is getting worse. On other washing machines that I have had emptying the filter has always got rid of smells like this. The smell is getting so bad that if I don't find a solution soon I will have to get a new washing machine, but I don't want to in case it is just something simple that I have missed.