where is the filter on an Indesit WG1030?

I have a wg1030, and sometimes the washing comes out wet, i suspect a blocked outflow filter, but there is no opening at the front. there is the normal panel at the front base, but behind that there is no filter chamber. there is a circular thing held on with screws but this just seems to hold something on behind the panel, and doesn't open, it is definitely not a filter chamber. so where or where is the filter chamber? before i pull the machine out and turn it upside down or take the back off, does anyone know where i should be looking.
thanks