About 3 months ago I took over being the treasurer of our local scout troop. Unfortunately our previous treasurer appears to have gone AWOL and doesn't respond to emails or calls with regard to handing over paperwork and cheque books etc. Hence this has resulted in us having no access to our bank accounts as he has the cheque book. I am hoping that he is just embarrassed about being behind in doing the accounts but I am wondering if there is anything more to it. 
The question how can we get access to the accounts. There are 2 signatories to the account with both needing to sign cheques and changes to authorities. Is it simply a case of talking to our bank and will they even discuss this matter with me as obviously I could be someone who just walked off the street!
Thanks