Fir u/s 420

I received a call from an Investigating Officer (SI) stating that an FIR has been lodged against me under section 419 and 420. I had worked in a PSBs for less than 2 years and resigned the service in year 2013. At that time I was appointed as a field officer on probation and my duty included doing inspection and signing on inspection sheet for KCC agriculture loan. During the tenure I had signed a document which as per police is impersonated i.e. some one has taken loan on other people documents by forging the papers. Now original landowner has filed FIR against me stating that I had forged the document for some financial motives. But in that case my only role was signing Inspection sheet as per my Branch Manager orders and I was not even involved in disbursement of loans. Now Investigating officer has told that they have dispatched some document to my mailing address and had ordered me to appear before him within 7 days of receiving the same for recording my statement. What should I do?. I have not done anything and negligence on my part was due to new joing and unwareness about the procedure. I am not even the part of that bank and presently in some other government service. what could be the consequences? Please guide.