I am not in Manchester anymore, but if you have suspicions about the background of somebody who could be Italian, you should ask him to see a copy of his ID document (driving licence, passport, etc.) and then check his name on the internet.
I wouldn't invest any money with somebody who wouldn't let me show his ID. Plus, if you know his full name, date and place of birth, you can ask the Italian Ministry of Justice for a "certificato penale", which is the equivalent of a British CRB check.