18,500 people have had their Pandemic Unemployment Payments stopped after investigations by the Department of Social Protection.
More than €4.3m has been repaid by people who wrongly claimed money under the scheme.
The PUP was launched in March and is capped at 350 euro a week.
New figures, released under the Freedom of Information Act, show 88,200 people had their applications for the payment refused.
18,500 people, who were approved for the payment, subsequently had it withdrawn after investigations by the department.
So far, more than 5,300 people have made repayments to the department after receiving PUP payments they were not entitled to.
A total of €4.37m has been reclaimed from these people.
Sinn Féin's spokesperson for social protection, Claire Kerrane, says the figures are “alarming”.
She said: “We need to know why these payments were revoked after they being received.
“And we also need to make sure that where the department are pursuing people for repayments, that those repayments are made in a fair manner.
“None of these people applied for the PUP for the sake of it. An awful lot people are suffering financially.
“They’ve lost their jobs, they’ve lost income.”
All cases of suspected PUP fraud are investigated by the department's special investigation unit, which includes 21 gardaí.