The 26-year-old man who has been speaking with police about the disappearance of British backpacker Grace Millane will be charged with her murder.
Auckland Police say he will remain in police custody until Monday morning when he will appear in the Auckland District Court.
Police said tonight that a further update can be expected after 10.30am tomorrow.
Tonight's statement said the Millane family have requested privacy at this time and will not be making any further statements at this stage.
Late this afternoon police announced they were questioning a man about the murder of Grace Millane, 22, who was last seen in Auckland's CBD a week ago.
"Just after 3pm this afternoon a 26-year-old man was located at a central Auckland address by police," Detective Inspector Scott Beard told media.
"He was brought back to the Auckland Central Police Station and is currently speaking to us in relation to the murder of Grace Millane.
"Sadly the evidence we have gathered to this point of the inquiry has established that this is a homicide.
"Grace's family has been advised of this development and they are devastated. The man is still being spoken to at this point.
"Obviously this means that we are treating Grace's disappearance as a homicide investigation.
"We still do no know where Grace is. We are determined to find her and return her to her family."
Today police have identified and secured a vehicle of interest and are now making inquiries to find out exactly where that vehicle has been, Mr Beard said.
"I know that the thoughts of all new Zealanders will be with Grace's family tonight, and I want to reassure everyone both here and abroad that New Zealand Police are determined to do everything we can to find her," he said.
The 26-year-old being questioned is the person of interest police mentioned yesterday.
"We know that he was with her on the Saturday evening and went to a number of places before going to the Citylife Hotel," Mr Beard said.
"We know that they were together from the time at the Sky City Hotel."
Earlier in the day police released photographs of a necklace and a watch in the hopes of finding her whereabouts. Her passport is also missing.
Police said enquiries into Grace's disappearance have not led to further confirmed sightings of her.
Grace was last seen wearing a black dress with white sneakers on Queen Street, in Auckland's CBD, at around 9.41pm last Saturday.
She failed to check in with family, which is very out of character for her, they say.
Detectives have since assessed Grace's belongings, which were left at the backpackers where she was staying.
Several of her belongings, including her passport, are missing and police believe it is likely Grace had these items with her, Auckland Police Detective Inspector Scott Beard said today.
The watch is a pale pink Casio Baby-G.
The necklace has been described as a round pendant on a silver chain with a green stone in the centre.
Police would like to hear from anyone who may have seen any of the items matching their descriptions over the past week.
Meanwhile, the scene examination at the Citylife hotel is continuing as detectives review hundreds of hours of CCTV footage.
Anyone with information about the missing items has been advised to contact 0800 676 255.