One of Australia's most high profile charities has admitted to underpaying nearly 250 staff members.

World Vision Australia reported itself to the Fair Work Ombudsman in December after discovering an error in its payroll resulting in about 200 casuals and 45 permanent employees being underpaid.

The charity World Vision Australia has admitted underpaying nearly 250 employees. Credit:Getty Images

The charity's acting chief executive Graham Strong told Nine News, The Sydney Morning Herald and The Age $8.9 million dollars had been set aside to pay staff back who were shortchanged after the incorrect award rates were applied to their roles.

"We apologise unreservedly for the error and have moved swiftly and decisively to rectify it," he said.