Police will spend time today with the mother of missing Aucklander Carmen Thomas now that she has arrived from Durban in South Africa.

Theresa Scott, 52, flew for 24 hours and landed yesterday to help in the search for her 31-year-old daughter, who has been missing since July 1, and to meet her grandson, Jack, 5.

"We'll get some background, what she loves, what could [have happened] and whatever else she can help us with, but we won't be pressing that from day one, obviously," said the officer in charge of the inquiry, Detective Inspector Mark Benefield.

"It's about having a liaison for the inquiry and keeping her informed as a mother would want to be informed ... and she's got a grandson to see out here. Coming such a long way, it must be terrible."

South African-born Ms Thomas, who worked as an escort at a gentlemen's club in Pakuranga, was last seen in Auckland at the beginning of the month. Her car was found in Hamilton days later.

Police have searched the Orakei Basin and parks near her Remuera home with dogs. They are also trawling through CCTV footage from Auckland and Hamilton businesses.

Asked how many hours of footage police had to go through, Mr Benefield said: "Thousands, I guess, once you think about how many hours in a day there are, how many buildings there are in a particular area ... and there's two cities."

The time it had taken to download each video and the fact that different businesses used different technology had caused some difficulties, he said.

Ms Thomas had also changed her appearance several times.

"If you consider the fact that you've seen more photos of Carmen with different looks on any given day - hair tied up, hair down, blonde hair, hair brown - it then takes a fair bit of work to get through and eliminate something.

"Sometimes it's a genuine person telling us that, 'Yeah, I saw her, she was there.' And we say, 'Okay, thank you,' do the video footage ... and we can't see it ... but, hey, they are genuine and we appreciate them coming forward."

Ms Thomas's relatives in the UK, where she used to live, are trying to organise a bank account for donations to cover the travel costs of her English-born mother.

Ms Thomas's aunt Carolyn Lavagna told Whitby Today the first the family heard of the disappearance was when another aunt received an email from the Herald.

"We looked on the newspaper's website and read the story about Carmen and rang Theresa.

"The police have apologised since. They didn't know she had any family and they didn't know how to get in touch with us.

"I want to think Carmen has had a meltdown and she has snuck off for some time alone and she will come back and say, 'Hi, I'm home'.

"But underneath, deep down, I think something may have happened and it's a negative thought."