(1)A public official or person acting in an official capacity, whatever his nationality, commits the offence of torture if in theUnited Kingdom or elsewhere he intentionally inflicts severe pain or suffering on another in the performance or purported performance of his official duties.
(2)A person not falling within subsection (1) above commits the offence of torture, whatever his nationality, if—
(a)in the United Kingdom or elsewhere he intentionally inflicts severe pain or suffering on another at the instigation or with the consent or acquiescence—
(i)of a public official; or
(ii)of a person acting in an official capacity; and
(b)the official or other person is performing or purporting to perform his official duties when he instigates the commission of the offence or consents to or acquiesces in it.
(3)It is immaterial whether the pain or suffering is physical or mental and whether it is caused by an act or an omission.
(4)It shall be a defence for a person charged with an offence under this section in respect of any conduct of his to prove that he had lawful authority, justification or excuse for that conduct.
(5)For the purposes of this section “lawful authority, justification or excuse” means—
(a)in relation to pain or suffering inflicted in the United Kingdom, lawful authority, justification or excuse under the law of the part of the United Kingdom where it was inflicted;
(b)in relation to pain or suffering inflicted outside the United Kingdom—
(i)if it was inflicted by a United Kingdom official acting under the law of the United Kingdom or by a person acting in an official capacity under that law, lawful authority, justification or excuse under that law;
(ii)if it was inflicted by a United Kingdom official acting under the law of any part of the United Kingdom or by a person acting in an official capacity under such law, lawful authority, justification or excuse under the law of the part of the United Kingdom under whose law he was acting; and
(iii)in any other case, lawful authority, justification or excuse under the law of the place where it was inflicted.
(6)A person who commits the offence of torture shall be liable on conviction on indictment to imprisonment for life.