Members of a leading Australian super fund will be forced to pay up after ‘undetected administrative errors’ saw them overpaid.

At least one member of QSuper has been overpaid by $90,000 and will have to give it back, with about 100 others overpaid and 200 underpaid.

Queensland Treasurer Jackie Trad is demanding answers from the public sector super fund, telling state parliament the mistakes are ‘totally unacceptable’.