Fifteen Malaysian immigration officers have been sacked and dozens have been suspended and redeployed after they appear to have deliberately disabled the international airport's passport check over a number of years.

Key points: Deputy PM says about 100 people are believed to be involved in sabotaging Malaysia passport control

Deputy PM says about 100 people are believed to be involved in sabotaging Malaysia passport control Fifteen suspects are in police custody, 14 immigration officers suspended and 20 under surveillance

Fifteen suspects are in police custody, 14 immigration officers suspended and 20 under surveillance The deliberate disabling of passport checks took place over six years, says immigration chief

Immigration Director-General Sakib Kusmi told Malaysian media on Tuesday that the dismissed and suspended officers may have links to human-trafficking syndicates.

"They deal online. The instructions come from overseas ... they can manipulate our system from outside. You can see this in our computers — the cursor moves without someone operating it," he said.

Ongoing technical faults regularly reported at Kuala Lumpur International Airport (KLIA), which led to hundreds of passengers at a time being waved through immigration without the normal checks, led to the three-month investigation.

The fifteen suspects were in police custody, Mr Sakib said, while 14 more officers were suspended and another 20 personnel, believed to be involved directly or indirectly in sabotaging computer systems over the past six years, were being monitored by immigration's intelligence division.

"We also transferred 63 officers out of our headquarters in Putrajaya and have prepared a new name list for personnel that are supposed to be stationed at airports," Mr Sakib said.

Last week, Malaysia's Deputy Prime Minister Ahmad Zahid Hamidi said about 100 people, including immigration officers, were believed to be involved in sabotaging the myIMMs system, which verifies if a passport had been stolen or reported lost.

An unnamed source told Turkey's Anadolu news agency that the myIMMs system had been found to have been deliberately taken offline once a day, forcing officers at passport control to manually screen passengers at KLIA.

Mr Sakib said the internal probe found that international syndicates tampered with KLIA's systems assisted by immigration and IT staff, as well as software vendors.

"The syndicate ... was able to control the movement of anyone entering or leaving the country," he said.

Singapore's Mediacorp had previously quoted an unnamed Home Ministry source saying that the high number of "breakdowns" indicated that many on international watch lists could have travelled through Malaysia undetected.