Hacking group Lizard Squad has leaked the itinerary and booking information of Malaysia Airlines (MAS) passengers, including that of a minister's, despite the airline denying its system has been compromised.

In a Twitter posting, Lizard Squad uploaded a screen capture of what appeared to be MAS’ email system.

Among the email is a booking for International Trade and Industry Minister Mustapa Mohamed to travel from the Sultan Abdul Aziz Shah Airport in Subang to Sultan Ismail Petra Airport in Kota Bahru.

The email title reads: "[#E5J-MM43VZ]: Fw: Booking Air Tkt SZB-KBR GOM Dato Sri Mustapa Mohamed Dept 26 Jan15. Urgent".

GOM refers to the government of Malaysia.

MAS does not operate out of Subang but its low-cost affiliate Firefly does.

MAS in a statement denied that its website was hacked and passenger data compromised.

"Malaysia Airlines assures customers and clients that its website was not hacked and this temporary glitch does not affect their bookings and that user data remains secured," it said.

Instead, the airline claimed that its Domain Name System (DNS) was affected and users were redirected to a compromised site.

Recreating MAS' media statement format on Twitter , the Lizard Squad issued a "media statement" of its own, in which the hackers accused the airlines of lying with regard to its passenger data being secured.

The group went on to mock the airline for not realising that information on its passengers had been compromised.

"Are you really that clueless? Wait until we package this nice present for you," it said in response to a MAS tweet that its data is secured.

Earlier today, Lizard Squad defaced MAS' website and signed off as the "Cyber Caliphate" with a message that read "ISIS will prevail" in reference to the Islamic State, an international terrorist organisation.

However, links to the Islamic State later appeared to be a red herring as Lizard Squad subsequently claimed responsibility and deliberately diverted users on MAS' defaced website to the Twitter accounts of UMG Gaming executives.

UMG Gaming is a platform that sells computer games on the Internet.

Lizard Squad last year targeted gaming platforms, including Sony's PlayStation network and Microsoft's Xbox's servers.