A 44-year-old man was arrested about 4.35pm and a baby that was inside the house has been recovered safey and is uninjured, police said.
Police were called to the house just after 5pm on Friday, Marlborough Area Commander Inspector Simon Feltham, said after a man arrived with a gun.
"The Police Negotiation Team has been at the address since last night, engaging with the man while he remained inside the house with the baby," he said.
"Police's focus has been the welfare of resolving the incident safely for all concerned and we are very pleased that has now been achieved.
"Police have also deployed tactical staff and other staff to achieve this outcome, and we've been supported by the New Zealand Defence Force."
Neighbours were asked to stay in temporary accommodation on Friday night.
There was no risk to the wider community, police said.
