The woman, from the Hunter Valley, asked staff at the branch to raise her withdrawal limit.

“Hers was set at $5000, and she was asking to increase it to over $50,000 to get the transfer done,” NAB customer adviser Tiffany Bailey said.

The bank’s staff told 9News this initially raised their alarms.

“Well, instantly, red flags were going off,” relief branch manager Vanessa Kruger said.

Adding to their suspicions, staff noticed the long-time customer was clutching her mobile phone.

Someone was listening in.

They quickly googled the phone number on the screen.

“It immediately came up with a result and said it was a likely scam,” Bailey said.

The scammer had been pressuring the recently widowed woman for days.

“She was scared and she broke down crying because she was being threatened,” Bailey said.

“They had actually remotely accessed her account and therefore convinced her they had given her $50,000 and she owed them the money,” Kruger said.

The criminal had coached her on what to say to the bank staff.

“I said to her, ‘can you please explain what that notebook is?’ and then she broke down,” she said.

“They were cues the criminal asked her to write down to convince us.”

Still too shaken by the experience to speak on camera, the target of this scam told 9News it was very upsetting and confusing, adding that she had no idea she was scammed.

“They are the biggest low lifes on the planet,” Kruger said.

“They prey on people who are vulnerable, try to trick them, it actually makes my blood boil.”

The consumer watchdog has warned Australians to be aware of the underhanded schemes.

“A remote access scam will begin with a contact out of the blue from someone who sounds pretty professional, telling you that there’s something wrong with one of your accounts,” ACCC deputy chair Catriona Lowe said.

“They are going to ask you to download software that will enable them to take control of your computer.”

The target of the scam returned a week later, with her bank balance intact.

“She had this massive smile on her face when she saw me, gave me a big hug,” Bailey said.