Residential Tenancies Act 1986

The landlord shall provide and maintain such locks and other similar devices as are necessary to ensure that the premises are reasonably secure.

Neither the landlord nor the tenant shall alter any existing lock or similar device, or add to or remove from the premises any lock or similar device, without the consent of the other given at the time that, or a reasonable time before, the alteration, removal, or addition is carried out.

Failure to comply with subsection (1), and contravention of subsection (2), without reasonable excuse, is each hereby declared to be an unlawful act.