CHARLESTON, W.Va. -- Charleston police are investigating about $750 in cash unaccounted for from a petty cash fund in the office of Charleston Police Chief Brent Webster.

Webster said officers use the cash for out-of-town trips and other expenses. But when an officer went to take money out of the fund last month, it was found that about $750 was missing.

Webster confirmed Thursday that police are investigating the fund. Police don't yet know if the money was lost or misplaced, or if someone took it. "At the very least, we have negligent mishandling [of the funds]," Webster said.

Two civilian employees who were in charge of the petty cash fund resigned late last week, Webster confirmed.