Airline Cathay Pacific has mistakenly sold first class tickets that can cost more than £10,000 for a fraction of the price - for the second time this year.
The Hong Kong flag carrier said it would honour the tickets, which it said had been sold in error on Sunday "because of an input issue" on the website.
The South China Morning Post reports lucky fare hunters snapped up tickets for $1,512 for a midday flight from Lisbon to London, followed by an afternoon flight in first class to Hong Kong.
The site pointed out full fares on similar routes cost $16,000 (£12,700).
The airline said in a statement: “We are aware of an error on some fares from Europe on our website because of an input issue. The sale of such fares was stopped immediately.
"We are looking into the root cause of this incident both internally and externally with our vendors. For the very small number of customers who have purchased these tickets, we look forward to welcoming you on board to enjoy our premium services.”)
It had already honoured tickets mistakenly sold on new year's day for a fraction of their value.
A ticketing error meant flights from Vietnam to the United States and Canada which would usually cost around $16,000 (£12,700) were sold for as little as $670 (£530).
Other airlines have made the same sort of mistake.
In 2014, Singapore Airlines agreed to honour around 400 business class flights to Australia which had been sold at economy prices.
Last year Hong Kong Airlines said it would do the same after a similar mistake was made.
Air Canada is involved in a lawsuit for refusing to honour a pricing mistake in 2015.