The fares wrongly appeared in systems on New Year’s Eve, with the flights, normally costing up to £12,600, being sold for just £534. The error was spotted by travel blogger Gary Leff, who found the cheap fares available from a number of Vietnamese airports to Cathay’s US gateways.

Leff warned his readers not to book accommodation or additional travel during the ticketed period as he thought Cathay would not honour the bookings, which were for the month of August.

However, the airline tweeted on Wednesday morning: “Happy 2019 all, and to those who bought our good - VERY good surprise ‘special’ on New Year’s Day, yes - we made a mistake but we look forward to welcoming you on board with your ticket issued. Hope this will make your 2019 ‘special’ too!”

Hong Kong’s South China Morning Post found 11 people who had bought 18 tickets before the error was corrected. They paid £22,000 for the premium fares, which should have cost £546,000.

This is the airline’s latest setback following November’s data breach, which affected 9.4 million customers during a three-month cyber attack. The carrier also suffered an embarrassment in September when an aircraft emerged from the paint shop with the brand name spelt incorrectly.