(12)The authorized Officer shall be responsible for their custody and also for re-imbrusing to the Board, in cash of any loss by theft, fraud, fire or any other cause:Provided that if in any case, after such inquiry, as the Board may make, the Board is satisfied that the loss was unavoidable and was not due to any negligence on the part of authorized officer, the Board may not insist on reimbursement of the amount of the loss by the officer concerned, and may write off such amount.
