Around 20 police investigators are combing through CCTV footage to track missing British backpacker Grace Millane's last movements before she disappeared over the weekend.
Grace's last confirmed sighting was at around 7.15pm on Saturday on Victoria Street in the Auckland CBD.
Police this afternoon released a CCTV image of her from Saturday evening.
Detective Inspector Scott Beard this afternoon said her disappearance was "out of character", after her family in the UK raised the alarm on Monday.
"At the moment, we don't have any evidence of foul play, but we keep an open mind," Detective Inspector Beard said.
He said Grace is approximately five foot six inches and 58kg with brown hair and brown eyes.
She was last seen wearing a black dress with what is believed to be white Converse sneakers.
Earlier today, her brother expressed the family's concern for Grace.
She came to New Zealand about two weeks ago and had been staying at the Base Hostel in central Auckland.
Grace had been keeping touch with her family back home through instant messenger, but has not been heard from since December 1.
Her family, who said they spoke to her "most days", became concerned when she failed to reply to birthday messages on Sunday.
Brother, Michael, told the BBC his sister graduated from the University of Lincoln in September and had planned to go travelling around the world.
Before coming to New Zealand she travelled as part of an organised group through South America for six weeks.
However she was travelling alone when she came to New Zealand about two weeks ago.
"It was what she wanted - she wanted to see the world," Michael said.
Her family reported her missing to New Zealand Police yesterday.
Michael said his sister last spoke to family last Thursday and has not posted anything on social media since.
The family have posted on Facebook in the hope that others travelling in New Zealand can help find her.
Thousands of people have shared the post.
Grace's father will fly to New Zealand, Michael said.