ST. PAUL — The chair of a Minnesota Senate committee that oversees the Department of Human Services has told the agency’s acting head that she or her successor need to figure out how they’ll repay the federal government for $25 million in apparent overpayments to two tribes for substance abuse treatment.

The overpayments were one of the main issues Tuesday at a hearing on the turmoil at the department, which has seen turnover in top management positions including the abrupt departure last month of Commissioner Tony Lourey.

Acting Commissioner Pam Wheelock gave the chair, Sen. Michelle Benson, few details to explain the leadership turnover.

But Benson warned Wheelock not to ask the Legislature for money to reimburse the feds for the overpayments to the tribes. She said taxpayers shouldn’t be on the hook.