A mother taken hostage at knifepoint in an Auckland mall had been on a dream trip with her daughter to see pop star Taylor Swift's concert when she was grabbed from behind.

Christchurch mum Laura Wheeler had only just arrived in Auckland on a trip planned as a birthday treat for her daughter, Jessica, 14, when they visited the Manukau Westfield shopping mall early yesterday.

The plan had been to call into the mall for a snack before heading to nearby Rainbow's End theme park and then onto 28-year-old pop starlet Swift's mega concert at Mt Smart Stadium.

But it was while her daughter was eating McDonald's nearby that the mum heard screams and was suddenly grabbed from behind.

The woman said she was then held at knifepoint for more than an hour with police being called to the scene at 8.50am.

"There were times when I thought, 'This is not even real, this is not happening', and then times when reality kicked in and I was like: 'What the hell is going on, I'm never going to see my kids again'," she told the Herald.

Police later praised her for bravery in remaining calm throughout the ordeal.

She said was thankful her daughter had not been standing next to her when she was snatched and that she was able to be taken away to safety when police arrived.

She was also extremely thankful to the police for ending the incident without anyone getting hurt.

A man was eventually arrested for allegedly taking the woman hostage at about 10am after police defused the situation through lengthy negotiations.

One witness photographed the man holding a knife to the Christchurch woman.

A man today briefly appeared at Manukau District Court charged with unlawfully detaining the woman without her consent.

The man was granted temporary name suppression, which prevented his name being published in the media.

He was remanded in custody and will reappear in court on Monday morning.

At a press conference after the incident, Counties Manukau Area Commander Inspector Adam Pyne said the woman was not known to the alleged offender and was "picked randomly".

Police were called at 8.50am to the hostage situation and were at the scene within minutes, he said.

"The first officer on the scene immediately began negotiations."

Police negotiated for about 40 minutes before the man dropped the knife, which had a 12.5cm blade, and released the victim.

The knife had been held to her throat and the Armed Offenders Squad had been called, he said.

"It took a long time but eventually they were able to diffuse the situation," he said.

The woman said she finished giving a statement to police by 12.30pm and then set about ensuring her daughter's birthday was not ruined by carrying on to Rainbow's End and Taylor Swift's concert.

And even though the rain fell down on the concert, it was "great".

"There was no way my daughter was missing out on that no matter what happened," the woman said.

"She deserves it."