Section 137

Any person who, being an officer of a prison, or a member of a police force, wilfully permits any other person within his lawful custody to escape-

(a) is, if such last-named person is charged with an offence punishable by death, or penal servitude or imprisonment for life, guilty of a felony, and is liable to imprisonment for seven years; and

(b) is, in any other case, guilty of a felony, and is liable to imprisonment for three years.