Making and possession of subversive documents
4.—(1)  Any person who, without lawful excuse, makes, causes to be made, carries or has in his possession or under his control any subversive document shall be guilty of an offence and shall be liable on conviction to imprisonment for a term not exceeding 10 years.
(2)  Every document purporting to be a subversive document shall be deemed to be a subversive document until the contrary is proved; and where in any prosecution under this section it is proved that a person made, was carrying or had in his possession or under his control a subversive document he shall be deemed to have known the nature and contents of the document:
Provided that no person shall be convicted of an offence under this section if he proves to the satisfaction of the court —
(a)that he was not aware of the nature or contents of the subversive document which he made, caused to be made, was carrying or had in his possession or under his control; and
(b)that he made, caused to be made, was carrying or had the subversive document in his possession or under his control in such circumstances that at no time did he have reasonable cause to believe or suspect that the document was a subversive document.