Justices Act 1886

If on the appearance of a person before a court or justices taking an examination of witnesses in relation to an indictable offence, either voluntarily or in obedience to a summons or upon being brought before them by virtue of a warrant, such person refuses to be examined upon oath concerning the matter, or refuses to take an oath, or having taken an oath refuses to answer such questions concerning the matter as are then put to the person, without offering any just excuse for such refusal, the court or justices may by warrant commit the person so refusing to prison, there to remain and be imprisoned for any time not exceeding 7 days unless in the meantime the person consents to be examined and to answer concerning the matter.