The disappearance of a British backpacker in New Zealand is being treated as murder, police have said.
"I want to reassure the public police are determined to do everything we can to find her".
Detective Inspector Scott Beard, from Auckland City Police, said at a press conference today: "Grace is no longer alive and this is a murder investigation".
Auckland City Police Detective Inspector Scott Beard said on Saturday: "Just after 3pm this afternoon (2am GMT) a 26-year-old man was located at a central Auckland address by police, he was brought back here to the Auckland Central Police Station and is now speaking to us in relation to the murder of Grace Millane".
'We last had contact with her on Saturday the 1st of December and as a family we've been extremely concerned for her welfare, ' said Mr Millane, who arrived in New Zealand on Friday morning.
DI Beard said police have released images of Ms Millane's watch and necklace and that her passport is also missing.
He added the "thoughts of all New Zealanders will be with Grace's family tonight".More news: China promises prompt action on US trade pact
The British backpacker, who graduated from the University of Lincoln in September, had been travelling alone in New Zealand for two weeks.
"Grace is a lovely, outgoing, fun-loving, family-oriented daughter", he said, adding that she was usually in touch with her family every day.
"We know that they were together from the time at the Sky City Hotel".
After visiting Peru, she arrived in New Zealand on November 20 and had been in near-daily contact with her family until 1 December.
Police said they brought that man into the central Auckland police station on Saturday afternoon for questioning.
"He was brought back to the Auckland Central Police Station and is now speaking to us in relation to the murder of Grace Millane".
Police had spoken to Millane's family this afternoon, Beard said.More news: Yemeni talks to start Thursday in Sweden: Houthi leader
Asked if the pair had met on the Tinder dating app, the detective said: "I'm not going to speculate on how they met".
"Several of her belongings, including her passport, are missing and police believe it is likely that Grace has these items with her".
They urged members of the public to come forward with any information. "Our thoughts are with her family at this bad time".
"Grace's family has been advised of this development and they are devastated".
"Our hearts go out to them".
'Grace is a lovely, outgoing, fun-loving and family orientated daughter'.More news: Here's how Wisconsin Republicans want to strip power from incoming Democrats