In all likelihood, you already know it because you have found the insurance papers at his home. If this is the case, and it’s certainly the most common occurrence, contact the insurer directly and, if your name appears as a beneficiary, you will receive the compensation foreseen in a few days.
If you cannot find any policies or simply don’t know, you can enquire at the Register of Death Cover Insurance Contracts. It is a public register, answerable to the Ministry of Justice, to which the insurance industry provides all the information.
If you have to deal with an inheritance, the notary public in charge will consult with the Register on line.