A Southern California Catholic school discovered its former principal and another nun stole an estimated $500,000 over a decade for their personal use, potentially using the money for travel and gambling.

The misappropriation of funds was discovered about six months ago, as the Los Angeles archdiocese performed a standard audit of the school ahead of Sister Mary Margaret Kreuper’s retirement as principal of St. James Catholic School. The school also discovered an old check had been deposited into an unknown account, and church leaders launched an internal investigation, the Long Beach Press-Telegram reported.

Last week, St. James families and parish members were notified with the investigation’s results: that Kreuper and another former teacher, Sister Lana Chang, had taken a substantial amount of money out of tuition and other school funds.

The women admitted what they had done and cooperated with the investigation, a statement by the Sisters of St. Joseph of Carondelet said. The order, whose sisters have taught at the school since it opened in 1918, said it would pay back the money, estimated at $500,000.

“Our community is concerned and saddened by this situation and regret any injury to our long relationship with the families of the school,” an order statement said. “The Sisters of St. Joseph both desire and intend to make complete restitution to St. James School.”