Suburban solicitor John Gordon Bradfield, 70, allegedly misappropriated clients' money through a pyramid-style scheme spanning 30 years from the late 1980s.

Mr Bradfield allegedly told most of his investors their money was secured in real estate, then issued false documents to support his claims.

Some properties were allegedly nominated as security for as many as 28 investors.

Mr Bradfield was due to appear in the Downing Centre District Court on Wednesday for a special hearing ahead of his trial next month.

However, his barrister, former Auburn MP Peter Nagel, told the court his client had suffered a "massive heart attack" and would not be fit to attend court for some time.

"He's spent six weeks in two hospitals, including two days in intensive care," Mr Nagel said.

Judge Gordon Lerve granted a short adjournment so that Mr Bradfield could provide records demonstrating his medical condition.

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

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

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