John Gordon Bradfield, 74, was at the centre of a drawn-out investigation and prosecution for misappropriating clients' and friends' money as part of pyramid-style scheme spanning 30 years from the late 1980s.

The former suburban solicitor suffered a heart attack in 2015, which delayed an anticipated NSW District Court hearing.

He subsequently pleaded guilty on February 5 last year to 10 charges of making false statements and using false instruments to obtain money.

On Friday, Judge Julia Baly heard submissions from the parties on the appropriate sentence.

His lawyer, former Auburn MP Peter Nagel, told the court his client had misappropriated $2.97 million as part of a "planned criminal activity".

"They were in most cases his friends but also his clients," Mr Nagel said of the victims.

He said there was "no evidence" Bradfield used the money for gambling or drugs but rather he was part of a Ponzi scheme "trying to pay other people off".

Bradfield "got deeper in debt" and lost $2.3 million of his own assets, including his interest in the matrimonial home, Mr Nagel said.

Mr Nagel said Bradfield came from a prominent family and was driven by "ego status" and "trying to keep his status".

His grandfather, John Bradfield snr, is known as the "father" of the Sydney Harbour Bridge.

Born in Brisbane in 1867, Bradfield snr oversaw the design and construction of the bridge and had the Bradfield Highway named in his honour.

Mr Nagel said Bradfield jnr could be sentenced to home detention and was effectively confined to his north shore home already because he had been required to remain close to home for court appearances since about 2014.

His client had been "punished for nine years waiting to get here today", Mr Nagel added.

A sick and frail-looking Bradfield appeared in court via audiovisual link.

Crown prosecutor Michael Barr said, "in my submission, clearly leaving aside the health issue, a substantial custodial sentence is required".

"The Crown doesn't dispute he's a very ill man," Mr Barr said.

But he said the offence was "too prevalent and too serious" for a custodial sentence not to be imposed to serve as a deterrent to others.

Deterrence was less relevant to Bradfield personally because he was no longer a solicitor and not in a position to reoffend, Mr Barr said.

Bradfield was struck off the roll of practising solicitors in 2009, a move that he did not oppose.

Mr Barr said a full-time custodial sentence was "the only ... available sentence" but the Governor could pardon Bradfield because of his ill health.

The court heard that Justice Health, which delivers healthcare to inmates, had provided two reports that said it was "in a position to look after the offender in custody".

Judge Baly said the case had been a "difficult matter for everybody".

She will sentence Bradfield on November 3.