I'm glad someone started something on this, I was just about to do it myself.
I would like to get all the facts straight in my head. As far as I can work out the implication is that David Mills used their jointly owned house's mortgage to launder some money that was a gift from Mr Berlusconi. They re-mortgaged the house to the tune of £400k, put that money in a fund and didn't declare it. This must instantly be a problem because the mortgage was joint so it was their money so she should have declared this but she didn't. That appears to be a fairly minor charge compared to the fact that a short while later they (he?) paid off with some money from Italy, allegedly from Berlusconi as a gift for testifying on his behalf in court. He wrote a letter to his accountant which seems to confirm this and later told Italian police that the letter was genuine and correct. Later on he changed his mind and said that he had been forced to say that by the police and the later was actually a made up scenario that corresponded to an unnamed friend. The money he did receive actually came from someone called Attanasio or something who has, several times, hotly denied this.
I think that's correct but if not please tell me. It looks as though he is in a lot of trouble and is desperately trying to lie his way out of it but basically all she has done is not declare her interest in this fund for which a slapped wrist may be all that is necessary. Of course it seems a bit surprising that he didn't happen to mention to her how he got the money to pay off the mortgage but you are never going to be able to prove that he did so what can you do?