I work in a bank and took advice on a similar situation recently. Basically if you never received the cheque then thats all you have to report / all that is your responsibility. If the cheque was inappropriately cashed/lodged, thats the credit unions problem and they have to chase that. The CU has no obligation or no right to release ANY information to you in relation to where what when the cheque was cashed etc. Its outside the legal guidelines for them to do that. It is up to them to advise the guards that they feel there may have been an inappropriate transaction on the account. The only reason for you to get involved is theft of post if thats what happened. As someone who works in a bank the best thing you can do is call and make an appointment with the branch manager (if a branch) and get it sorted. You ll get the run around on the phone. Its not your fault and not your issue if you are genuinely not complicit in the fraud, however, you have to understand that they need to reassure themselves of this. Put your foot down, or failing that phone Gerry Ryan !