The authority said on Tuesday (8 October) it had taken “urgent action” in response to what it says it believes was “attempted fraudulent activity” relating to refunds for Thomas Cook customers.

“We are informing the police of this activity and are implementing further verification checks to protect consumers,” said the CAA.

“Where we see evidence of fraud, we will seek to prosecute any individuals or organisations involved. If you have made a claim directly with us, then your claim is being processed and you do not need to take any action.”

Delayed a week to allow the CAA to focus on repatriating the more than 140,000 Cook passengers left stranded overseas when the iconic operator collapsed on 23 September, the refund process got off to a shaky start on Monday morning (7 October) when the online claim form struggled to handle demand.

However, by 1pm on Tuesday, the CAA said it had received 100,000 refund submissions, adding the first automatic direct debut refunds had been paid out to Cook customers.

The CAA is urging Cook customers to ensure they only apply for refunds through the official channel – thomascook.caa.co.uk/refunds.

“Our role is to protect the consumer and this is our foremost priority,” the authority added. “We will not hesitate to take the necessary action to do so.

“Therefore, please only make claims directly through the official dedicated website. 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.

“We will publish further updates as soon as more information is available, and we remain committed to processing refunds to Thomas Cook customers quickly and securely.”