An autopsy couldn't determine if a washed-up foot belonging to accused Sydney fraudster Melissa Caddick was separated as a result of decomposition or force, an inquest has been told.

The 49-year-old vanished in November 2020, hours after the Australian Investment and Securities Commission (ASIC) raided her Dover Heights home, in Sydney's eastern suburbs.

Three months later, her decomposing foot washed up on Bournda Beach, on the NSW south coast, and police believe Ms Caddick is dead.

Liquidators are attempting to recoup some of the $23 million she allegedly stole from investors through a Ponzi scheme, as a parallel case proceeds through the Federal Court.

During an opening address, Counsel Assisting the coroner Jason Downing said while DNA analysis confirmed the foot belonged to Ms Caddick, it was not possible to determine how it became separated.

He said the date and place of Ms Caddick's suspected death are the subject of "significant uncertainty" and flagged the possibility of the inquest resulting in an open finding.

The court heard the last verified sighting of Ms Caddick was by ASIC and AFP officers just before 6.30pm on November 11, 2020, when the raid was completed.

But any information on her whereabouts between then and when she disappeared "relies almost entirely" on accounts from her husband, Anthony Koletti, and her son, who will be known in the inquest as "Witness B".

Deputy State Coroner Elizabeth Ryan earlier acknowledged the presence in court of Mr Koletti and her parents, Ted and Barbara Grimley.

"This inquest, as we all know, is taking place against a particular background, which is that many people have been financially harmed, allegedly, because of Melissa Caddick's activities," she said.

"Having said that I know she is also a daughter and a wife and a sister and a mother and I am sure that her disappearance from your lives has brought shock and bewilderment and grief which you've been living with for the past two years."

Magistrate Ryan said an inquest was a painful experience for a family.

Mr Downing foreshadowed evidence from friends who observed Ms Caddick to be under significant financial pressure in 2020.

The court heard that, during a walk to cliffs, she once remarked: "If I'm going to end it, it's going to be here".

She had also previously made a separate reference to being found at "the gap" if it "all gets too much".

Mr Downing said there will be evidence that after ASIC commenced its investigation, Ms Caddick made inquiries through a friend about shredding services.

The court heard Ms Caddick's relatives have expressed concerns about how she was treated during the 12-hour raid.

But Mr Downing said the evidence does not support the suggestion she or Mr Koletti were "mistreated" and that she appeared calm, compliant and with no signs of anxiety or depression.

The couple went to their backyard to have coffee, tea or a cigarette several times.

The inquest is expected to hear evidence about ASIC's risk assessment protocols prior to the search.

It will continue for the rest of the week and then resume for a second week on September 26.