Legislation that allows the police to detain suspects without charge for upto 48 hours without a warrant was passed on Tuesday.
The previous limit was 24 hours.
Presenting the bill in parliament, the Environment Minister Anura Priyasharshana said:
"This is to curb organised crime. If there is a need to extend the detention by another 24 hours, it could be done by a magistrate based on a certificate produced by the police."
The Prevention of Terrorism Act - of far greater relevance to Tamils - allows indefinite detention.