Ariston Margherita CDE 12x Washing Machine

My machine is 3 years old and has a usage of about once a week. Recently we have noticed that there is water in the drum. A couple of hours after a wash cycle clear water starts to appear and at times it the level comes above the door. I’ve checked the filter and its ok. If a set the selector to drain the water is pumped out but more appears in a couple of hours. As a test I’ve turned off the hot and cold water supplies, one at a time, and the problem only appears when the cold water supply is turned on. I think this must indicate a faulty electro valve in the machine.
I’d appreciate if somebody could confirm this and tell me how to fix it. I’ve searched the web but can’t find any reference to this model and there doesn’t seem to be an Ariston web site for Ireland and the UK???
Thanks in advance
Anthony (Ireland) ❓