Related Rule
Practice Relating to Rule 99. Deprivation of Liberty
Section B. Deprivation of liberty in accordance with legal procedures
In its judgment in the Baluch case in 1968, the Supreme Court of Pakistan stated:
It is well-settled that a law is not to be given retrospective effect unless it is expressly or by necessary intendment made retrospective … In the present case, what was under challenge in the High Court, was the validity of the detention order passed on the 11th August 1966, which was made before the present amendments came into force. The validity of that order has, of necessity, therefore, to be judged on the basis of the law prevailing on that day. 
Pakistan, Supreme Court, Baluch case, Judgment, 24 May 1968.