The Supreme Court of Canada struck down Friday the government's right to detain foreign terrorism suspects indefinitely and without trial, saying the system violates the country's bill of rights.
The Justice Department had insisted that the "security certificate" program is a key tool in the fight against global terrorism and essential to national security.
In a 9-0 judgment, the high court found that the system violates the Charter of Rights, but suspended the judgment from taking effect for a year, to give Parliament time to write a new law complying with constitutional principles when dealing with terror suspects.
The system was challenged on constitutional grounds by three men from Morocco, Syria and Algeria, all alleged by the Canadian Security Intelligence Service to have ties to al-Qaida and other terrorist groups. All deny any such ties.