Territorial Application: Wales Part 4 .Police Powers Section 161: Entry and search of premises for purposes of arrest
462.This section gives a police constable power to enter and search premises, with a view to arresting a person under an extradition arrest power. The term "extradition arrest power" is defined for the purposes of this Part in section 174 below.
463.If a police constable has the power to arrest a person in connection with an extradition matter (subsection (1)), he may enter and search any premises to exercise this power, subject to certain conditions. He must have reasonable grounds for believing that the person in question is on the premises (subsection (2)). The power to search is allowed only insofar as it is reasonably necessary to effect arrest (subsection (3)).
464.Under subsection (4) a police constable may then seize and retain anything which is on the premises where he has reasonable grounds to believe:
	that it has been obtained as the result of an offence or is evidence of an offence (including offences committed outside the United Kingdom); and
	that it is necessary to seize it to avoid the evidence being lost or interfered with in any way.
465.Subsection (6) covers the situation where the premises in question include multiple dwellings (for example, a block of flats). A police constable is allowed, in this situation, to enter and search only the communal areas of the premises and any dwelling where he has reasonable grounds to believe the person in question might be.