Last week my credit card statement arrived in the post and through the envelope window, you could clearly see my card number. Is that a fraud risk?

Your card details should not be viewable through the envelope window but it is not a big security risk.

Your card cannot be copied with the information on your statement - ie your name, address and card number. A fraudster would also need the expiry date and the security number which is on the reverse of your card in order to make a purchase over the phone. If the fraudster tried to make an online transaction they would also need the password you need on the card.

Nevertheless, the your card company shoul not send coprrespondence to you like this. I suggest you write to them - but don't expect a reply!