DELIBERATE interference with the immigration computer system at Kuala Lumpur International Airport may have been organised for the benefit of people traffickers and militants.

Fifteen immigration officers suspected of compromising Malaysia's passport system are in police custody, a further 14 have been suspended and another 20 are being monitored by the department's intelligence division.

The arrests and disciplinary action follow an investigation into frequent crashes on computers connected to Interpol, which facilitates international police co-operation.

The Straits Times reported Deputy Home Minister Nur Jazlan Mohamed as saying there was a high possibility of official collusion in the almost daily breakdown of the computer system.

During those times, hundreds of passengers were waved through immigration without the normal checks.

Immigration Director-General Sakib Kusmi told Malaysian media that sabotage of the computer system could have been occurring for the past six years.

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

Money is believed to be the motivation of those allegedly involved.