
The Prevention of Terrorism Act allows authorities to detain terrorism suspects without charge, and the political opposition as well as legal and rights groups had urged its withdrawal.
"It introduces long-term detention without trial, is open to abuse and is a grievous blow to democracy," opposition lawmaker N. Surendran said.
Authorities have expressed increasing alarm in the wake of the Islamic State (IS) group's bloody jihad in Syria, which police say has drawn dozens of recruits from traditionally moderate, Muslim-majority Malaysia.