R (on the application of Kelly and another) v Secretary of State for Justice Re Gibson [2008] EWCA Civ 177, [2008] All ER (D) 172 (Mar)
It will take very clear and unambiguous words in a statute before the courts will construe it as empowering the state to deprive an individual of his liberty.
There is no rule or principle to the effect that the courts will avoid a purposive construction on account only of the fact that the statute in question touches the criminal law. It follows that, in the context of criminal sentencing, the court may read words into a statutory instrument to correct a drafting omission.