The said breach has hit an estimated 9.4 million people.

The company said in a statement that data like passport numbers, expired credit card details and email addresses were among the ones siphoned by hackers.

However, it said that there were no evidence that the stolen data were misused.

Apologising to its customers, the airline's chief executive Rupert Hogg said in a statement: "We are very sorry for any concern this data security event may cause our passengers.

"We acted immediately to contain the event, commence a thorough investigation with the assistance of a leading cybersecurity firm, and to further strengthen our IT security measures.

Meanwhile, Cathay Pacific shares took a hit on Thursday following the revelation.

The shares nosedived six percent in Hong Kong, reports said.

Other airlines to have suffered a data breach in recent times are the Delta Airlines and Air Canada.

While Air Canada app was compromised in August, Delta Airlines said that a cyber attack in April exposed credit card details of thousands of its customers.

The British Airlines too suffered a similar fate last month as hackers hacked into its website and app and stole data.

Image: facebook.com/cathaypacificHK