He asked for directions to Devonport and then lingered, asking how to first get to Takapuna from Milford.
"Mum answered his questions and then went home. She discovered the next day that her wallet was missing, that somebody had taken it from her car,' Ms Lush said.
"She was so upset, she had a heart attack.
"It was a real deliberate, manipulative and very very cold and calculated theft."
Ms Lush's mother also had $200 cash in her wallet.
She said her mother was particularly distressed because she was always so vigilant with her safety and finances.
"Luckily when she realised the wallet was missing she called and cancelled her Eftpos card. If she hadn't they would have probably cleaned her out -- and that would have killed her.
"Mum's not handling this very well at all."
Ms Lush said elderly people were "sitting ducks" for the thieves.
"It's easy money for them. But please don't do it, please. Old people need their money, just try to have a little bit of a sense of right and wrong."
Detective Senior Sergeant Stan Brown explained how the thieves were getting access to the victim's accounts.
He said as the victim buys groceries and pays with an Eftpos card, a female offender will "shoulder surf" and watch the elderly woman enter her pin.
"As the elderly woman enters her pin number, the woman is watching and either filming it with her own cellphone, or making a note of the victim's pin number into the cellphone," Mr Brown said.
"The offender then 'decides' not to buy her own groceries, and leaves the shop immediately.
In six cases, the victim has then been followed home by the offenders.
"Shortly after arriving home, a man will knock on the door and attempt to distract the victim by asking the elderly lady to come out of the house and check for a missing car, or to investigate a strange noise.
"During this time a second man will steal the victim's purse from her house. Straight away the offenders make multiple withdrawals from the victim's account."
Five victims had been identified so far and it was expected more would emerge when news of the scam spread.
The supermarkets where the victims have been shopping vary across the North Shore, however several have occurred in Browns Bay and one took place in Westgate in West Auckland.
Some of the victims' purses have been stolen after being approached in the supermarket carpark, rather than at their home.
"This is appalling, these criminals are targeting one of our most vulnerable groups, invading their privacy, then their homes, stealing their money and leaving them traumatised," Mr Brown said.
"The effects of a crime like this on an elderly person cannot be underestimated. They must be stopped and we need the public to help us."
Police believe that a group of three offenders are responsible, a woman and two men.
"We've launched a specific operation to investigate these crimes -- Operation Nitro. Investigators on the team are in the process of making numerous enquiries and gathering all the evidence," Mr Brown said.
"We do believe that there may be more victims that haven't yet come to the police and we'd really encourage anyone who has been a victim to please ring the 0800 number.
"Whilst this type of crime is alarming, fortunately it is not common on the North Shore but we fully understand that there will be elderly people who are frightened by this.
"If you're scared, talk to a relative, Age Concern or Neighbourhood Support. Your local community police will also be able to offer advice and reassurance."
THE OFFENDERS:
The female who stands behind elderly women in supermarket checkouts is a Maori or Pacific Islander in her 20s with shoulder-length wavy hair.
She is working with two males in their 20s.
They may be travelling in a silver or white car.
The men who have approached the victims at their homes have been described as being smartly dressed and well-spoken.
Anyone with information is asked to call the Operation Nitro on 0800 464 876 (0800 4 NITRO).
