Amnesty International has urged Malaysia to free five activists held under the tough Internal Security Act (ISA) after a rare recommendation for their release by the ISA review board.

The London-based rights advocates said "the review board's statement highlights the misuse of the ISA and provides an ideal opportunity for the government to act to secure the immediate and unconditional release of the five detainees."

Tian Chua, Saari Sungib, Hishamudin Rais, Lokman Nor Adam and Badrul Amin Bahron were recommended for release in early December by the review board of the ISA, a controversial law that among other things allows indefinite detention without trial.

The recommendation followed a Federal Court ruling Sept 6 that three of the detainees had been unlawfully detained from the beginning.