Four employees of an Owego bank office may have taken up to a half-million dollars over a period of nearly seven years.

Assistant United States Attorney Thomas Walsh estimates the total amount stolen from the Chemung Canal Trust Company was between $400,000 and $500,000.

Earlier accounts indicated that the amount taken in the embezzlement scheme was more than $325,000.

Speaking on WNBF Radio's Binghamton Now program, Walsh said an audit conducted at the Owego bank branch at 203 Main Street after the September 2011 flood revealed the actual cash on hand was "much less" than records had indicated.

Walsh said although three former workers at the bank have pleaded guilty to felony embezzlement counts in the case, a fourth employee also admitted to stealing money.

The prosecutor said the amount she stole was "nominal" compared to what was taken by the three employees who were prosecuted.

Walsh would not be specific on how much that teller took but he said full she had made full restitution.

Walsh said all four women ultimately were interviewed by the FBI and appeared to give truthful information regarding their roles in the embezzlement.

Walsh said in more than 30 years as a prosecutor, he had not previously seen a case in which four employees at one office had participated in this type of scheme.

Here's how the embezzlement occurred: cash deposit slips were prepared by the employees, then money was taken from teller drawers or the bank vault. That money the was deposited into accounts connected to the four women who at the time were working at the bank. When the money was deposited into their accounts, they then had access to the stolen cash.

Walsh said had it not been for the audit spurred by the flood, it's quite possible the embezzlement would be continuing to this day.

Two Owego women, Megan Horton and Gwenn Gooding, pleaded guilty in the case last week. Shannon Moore of Athens, Pennsylvania, pleaded guilty to felony bank embezzlement late last month.

Sentencing for the three has been scheduled for April and May in Binghamton federal court.