One of Melissa Caddick's investors has told her inquest she became so alarmed by something fishy she had been told, that she wanted her money back immediately.

Dominique Ogilvie had a chance encounter with someone in the waiting room of a dental specialist in Sydney in August 2020, when they struck up a chat about financial advisers.

Ms Ogilvie told the NSW Coroners Court on Tuesday the woman asked if she was using Melissa Caddick's services.

"And I said yes ... she said 'I need to speak with you'.

"'I said 'oh'. And then I was called into the endodontist."

The pair exchanged phone numbers and Ms Ogilvie - extremely alarmed by her tone - sent a message: "Dying to talk to you."

By that stage Ms Ogilvie had invested $2.5 million with Ms Caddick's fake company Maliver.

Later that day the woman revealed Ms Caddick was using her Australian Financial Services Number illegally.

Ms Ogilvie had met the conwoman while holidaying in Aspen Colorado staying in an apartment Ms Caddick claimed to own.

In April she invested $450,000 and the documentation she received purported "good" profit, she said.

Later that month she injected an additional $550,000, followed by $1 million.

"Big birthday present just gone into your account," she texted Ms Caddick, telling the inquest she was being a "bit smart, sarcastic".

She continued to invest before the fateful conversation raised the alarm bells, and as she later told ASIC made her think "something smells here, I need to get my money out".

Ms Ogilvie is one of the few to recoup her money plus an additional purported profit of $380,000.

On September 14 she was formally interviewed by the Australian Securities Investment Commission, but still wasn't quite sure of the size of the fraud, she said.

She denied ever having told Ms Caddick about the ASIC investigation into her.

After she received her investment back she said she cut off communication with her former friend.

'I wasn't able to speak with her after that. I felt uncomfortable. Cleaner and easier for me not to have any contact," she said.

Ms Caddick pretended she was investing her victims' wealth by appearing to set up CommSec trading accounts and forging documents to claim she was generating profits.

She preyed on mostly friends and family, and stole up to $30 million between 2013 and 2020, counsel assisting Jason Downing SC has told the inquest.

Her husband Anthony Koletti reported the 49-year-old as missing some 30 hours after he says she walked out of their home for the last time on November 12 about 5.30am to go for a walk.

His stories to police about the last time he saw his wife have been inconsistent and subject to intense scrutiny during the inquest.

In February 2021 Ms Caddick's decomposing foot encased in an Asics shoe washed ashore at Bournda Beach on the NSW south coast, about 400km south of Sydney.

© AAP 2022