The Civil Aviation Authority (CAA) has said that fraudsters are suspected of targeting the Thomas Cook refund website.
The CAA said they have taken “urgent action” over the suspicious online activity and further verification checks have been added.
More than 10,000 claims have been made on the refund website since Monday morning and many claims have been low level, which has indicated fraud.
Dame Deirdre Hutton, who chairs the CAA said, “This morning we have taken urgent action in response to what we believe is attempted fraudulent activity in relation to refunds for Thomas Cook customers.
“If you have made a claim directly with us, then your claim is being processed and you do not need to take any action.”
Dame Hutton added, “Please help us to combat the risk of fraud by not submitting your details to any other website.
“Our focus is on getting money back to the right people as soon as possible and combating fraud in every way possible.”