Law Enforcement (Powers and Responsibilities) Act 2002 No 103
Current version for 23 March 2020 to date (accessed 6 June 2020 at 12:38)
Part 2 Section 10
10   Power to enter to arrest or detain someone or execute warrant
(1)  A police officer may enter and stay for a reasonable time on premises to arrest a person, or detain a person under an Act, or arrest a person named in a warrant.
(2)  However, the police officer may enter a dwelling to arrest or detain a person only if the police officer believes on reasonable grounds that the person to be arrested or detained is in the dwelling.
(3)  A police officer who enters premises under this section may search the premises for the person.
(4)  This section does not authorise a police officer to enter premises to detain a person under an Act if the police officer has not complied with any requirements imposed on the police officer under that Act for entry to premises for that purpose.
(5)  In this section—
arrest of a person named in a warrant includes apprehend, take into custody, detain, and remove to another place for examination or treatment.