Deputy Prime Minister Datuk Seri Dr Ahmad Zahid Hamidi today stressed that only illegal immigrants slipped through immigration at the KL International Airport.

Ahmad Zahid, who is also Home Minister, said no terrorists slipped through and that those who sabotaged the myIMMs immigration system at KLIA were not involved any form of terrorist activity as had been reported by an international news agency on Tuesday.

"We are not protecting any immigration officer (involved in sabotaging the system) no matter the rank.

"In fact, the orders issued to conduct investigations with the cooperation of the Malaysian Anti-Corruption Commission and the Royal Malaysia Police are because drastic action must be taken to overcome such breaches," he said.

Speaking to Malaysian journalists after delivering the keynote address at the 34th joint Japan-Malaysia Economic Association and the Malaysia-Japan Economic Association (JAMECA-MAJECA) conference here, Ahmad Zahid said monitoring would be stepped up all entry points into the country to ensure such breaches did not recur.

On the sacking of 15 immigration officers on Tuesday, he said they would have to face the law if they had committed offences apart from internal disciplinary action.

Immigration Department director-general Datuk Seri Sakib Kusmi said in Sepang, Selangor on Tuesday that 37 immigration officers had been penalised since February over the sabotage, with 15 of them sacked, 14 suspended and eight having their salary raise frozen.

The first series of the Auditor General's Report of 2015 had stated that the myIMMs developed to support the major operations of the Immigration Department was less satisfactory and did not meet its objective.