Defence of a bank manager implicated in a fraud case

Being a branch manager of a nationalized bank, my father worked with great honesty and integrity. In his 30 years career working with the same bank, he never involved in any fraudulent activity. He also received regular appreciation from his supervisors, which also involved recognition and awards in some cases. Few years back he was posted in a remote area, and with his hard work he tried to rejuvenate the almost dead branch with better service and financial literacy for the locals. In spite of his repeated intimation to higher authority, the branch was working with half the sanctioned strength of staff. To provide service to long queue of customers, sometimes his officer used his credentials. But the credentials were never shared. During one of the same scenarios the officer made some fund transfer to his personal account which was a fraudulent activity and my father is implicated because of his credentials used and he is in suspension for last 4 months. During internal investigation it is revealed that the officer was involved in such activity in other branches as well with his own credential and he has some companions as well. All of them are currently suspended. During internal investigation the officer confessed his crime in written form and also wrote that my father has no role in this and he is innocent. We now want to know if there'll be an FIR against my father or if he will be arrested? What options do we have at this moment?