Guardia di Finanza and IVEI tax (Rome)

The other morning we were surprised to find two Guardia di Finanza ringing our door bell. They "invited" us to go to their office with all the documentation we have about property and assets in the UK. They explained that there is a disclosure agreement with the UK tax authorities. We do have a commercialista and have always given him all the details of property, income etc. He was most surprised as we have done our dichiarazione and paid our taxes here on time.

Reading the blogs elsewhere it is possibly to do with a new tax IVEI which although no one tells you about, you must pay and be fined for not paying if you don't. We have sold our UK property so I think we are OK, but it did give us a fright.

I wonder if anyone else has had this experience, or knows more about this tax.