More than half of the around 7,000 auxiliary police officers (APOs), which include those from Aetos and Certis Cisco, are Singaporeans.
And no APOs who are Malaysians are deployed at Singapore's land checkpoints.
This is a deliberate move by the Government, despite manpower challenges, Minister for Home Affairs and Law K. Shanmugam assured the House yesterday.
He was addressing concerns raised by Workers' Party's Ms Sylvia Lim (Aljunied GRC) on the supposedly large number of APO positions filled by Malaysians.
"One officer recently told me that the ratio allowed is five Malaysians to one Singaporean and I wonder if that is true," she asked.
Ms Lim also questioned if there are guidelines available for the deployment of these officers, particularly at checkpoints.
"For example, at immigration checkpoints, are there Malaysians checking their fellow Malaysians and what are the risks?"
Only Singaporeans, Singapore permanent residents who are Malaysian citizens, or Malaysians are eligible to be an APO, Mr Shanmugam said. "We have deliberately maintained a Singaporean majority over the years and we will continue to do so," .
These officers are deployed in a range of functions, including protecting sensitive installations and supporting police deployment at major events.
"They are used as a complement for police resources to allow the police to perform core functions like crime-fighting and countering terrorism," he added.
But "we are conscious of the implications of hiring and deploying Malaysian APOs".
When it comes to land checkpoints, he said, his ministry requires all APOs to be Singaporeans.