Where a person has committed a relevant offence, any other person who, knowing or believing him to be guilty of the offence or of some other relevant offence, does without lawful authority or reasonable excuse any act with intent to impede his apprehension or prosecution shall be guilty of an offence.
In this section and section 5 below, " relevant offence " means—
If on the trial of an indictment for a relevant offence the jury are satisfied that the offence charged (or some other offence of which the accused might on that charge be found guilty) was committed, but find the accused not guilty of it, they may find him guilty of any offence under subsection (1) above of which they are satisfied that he is guilty in relation to the offence charged (or that other offence).
A person committing an offence under subsection (1) above with intent to impede another person's apprehension or prosecution shall on conviction on indictment be liable to imprisonment according to the gravity of the other person's offence, as follows:—
No proceedings shall be instituted for an offence under subsection (1) above except by or with the consent of the Director of Public Prosecutions: . . .
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